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Scientific American Supplement, No. 421, January 26, 1884
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SCIENTIFIC AMERICAN SUPPLEMENT NO. 421



NEW YORK, JANUARY 26, 1884

Scientific American Supplement. Vol. XVII., No. 421.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.

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TABLE OF CONTENTS

I. ENGINEERING AND MECHANICS.—Furcot's Six Horse Power Steam Engine.—With several figures. 6714

Foot Lathes.—With engraving. 6715

Endless Trough Conveyer.—2 engravings. 6715

Railroad Grades of Trunk Lines. 6715

English Express Trains.—Average speed, long runs, etc. 6715

Apparatus for Separating Substances Contained in the Waste Waters of Paper Mills, etc.—2 figures. 6717

II. TECHNOLOGY.—An English Adaptation of the American Oil Mill.—Description of the apparatus, and of the old and new processes.—Several engravings. 6716

Large Blue Prints.—By W.B. Parsons, Jr. 6717

III. ELECTRICITY, ETC.—Electrical Apparatus for Measuring and for Demonstration at the Munich Exhibition.—With descriptions and numerous illustrations of the different machines. 6711

A New Oxide of Copper Battery.—By F. De Lalande and S. Chaperon.—With description and three illustrations. 6714

IV. MATHEMATICS, ETC.—To Find the Time of Twilight.—1 figure. 6720

A New Rule for Division in Arithmetic. 6725

Experiments in Binary Arithmetic. 6726

V. ARCHAEOLOGY.—Grecian Antiquities.—With engravings of the Monument of Philopappus.—Tomb from the Ceramicus.—Tower of the winds.—The Acropolis.—Old Corinth.—Temple of Jupiter.—The Parthenon.—Temple of Theseus, etc. 6721

VI. NATURAL HISTORY, ETHNOLOGY, ETC.—Poisonous Serpents and their Venom.—By Dr. Archie Stockwell.—A serpent's mouth, fangs, and poison gland.—Manner of attack.—Nature of the venom.—Action of venom.—Remedies. 6719

Ethnological Notes.—Papuans.—Negritos. 6720

VII. HORTICULTURE, BOTANY, ETC.—The Hornbeams.—Uses to which the tree is put.—Wood for manufactures.—For fuel.—Different varieties.—With engravings of the tree as a whole, and of its leaves, fruit, flowers, etc. 6724

Fruit of Camellia Japonica.—1 engraving. 6725

VIII. MEDICINE. SANITATION, ETC.—House Drainage and Refuse. Abstract of a lecture by Capt. Douglas Galton.—Treating of the removal of the refuse from camps, small towns, and houses.—Conditions to observe in house drains, etc. 6717

Pasteur's New Method of Attenuation. 6718

Convenient Vaults. 6719

IX. MISCELLANEOUS.—Spanish Fisheries.—Noticeable objects in the Spanish Court at the late Fisheries Exhibition. 6722

Duck Shooting at Montauk. 6723

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ELECTRICAL APPARATUS FOR MEASURING AND FOR DEMONSTRATION AT THE MUNICH EXHIBITION.

Apparatus for use in laboratories and cabinets of physics were quite numerous at the Munich Exhibition of Electricity, and very naturally a large number was to be seen there that presented little difference with present models. Several of them, however, merit citation. Among the galvanometers, we remarked an apparatus that was exhibited by Prof. Zenger, of Prague. The construction of this reminded us of that of other galvanometers, but it was interesting in that its inventor had combined in it a series of arrangements that permitted of varying its sensitiveness within very wide limits. This apparatus, which Prof. Zenger calls a "Universal Rheometer" (Fig. 1), consists of a bobbin whose interior is formed of a piece of copper, whose edges do not meet, and which is connected by strips of copper with two terminals. This internal shell is capable of serving for currents of quantity, and, when the two terminals are united by a wire, it may serve as a deadener. Above this copper shell there are two identical coils of wire which may, according to circumstances, be coupled in tension or in series, or be employed differentially. Reading is performed either by the aid of a needle moving over a dial, or by means of a mirror, which is not shown in the figure. Finally, there is a lateral scale, R, which carries a magnetized bar, A, that may be slid toward the galvanometer. This magnet is capable of rendering the needle less sensitive or of making it astatic. In order to facilitate this operation, the magnet carries at its extremity a tube which contains a bar of soft iron that may be moved slightly so as to vary the length of the magnet. Prof. Zenger calls this arrangement a magnetic vernier. It will be seen that, upon combining all the elements of the apparatus, we can obtain very different combinations; and, according to the inventor, his rheometer is a substitute for a dozen galvanometers of various degrees of sensitiveness, and permits of measuring currents of from 20 amperes down to 1/50000000 an ampere. The apparatus may even be employed for measuring magnetic forces, as it constitutes a very sensitive magnetometer.



Prof. Zenger likewise had on exhibition a "Universal Electrometer" (Fig. 2), in which the fine wire that served as an electrometric needle was of magnetized steel suspended by a cotton thread. In this instrument, a silver wire, t, terminating in a ball, is fixed to a support, C, hanging from a brass disk, P, placed upon the glass case of the apparatus. It will be seen that if we bring an electrified body near the disk, P, a deviation of the needle will occur. The sensitiveness of the latter may be regulated by a magnetic system like that of the galvanometer. Finally, a disk, P', which may be slid up and down its support, permits of the instrument being used as a condensing electrometer, by giving it, according to the distance of the disks, different degrees of sensitiveness. One constructor who furnished much to this part of the exhibition was Mr. Th. Edelmann of Munich, whose apparatus are represented in a group in Fig. 3. Among them we remark the following: A quadrant electrometer (Fig. 4), in which the horizontal 8-shaped needle is replaced by two connected cylindrical surfaces that move in a cylinder formed of four parts; a Von Beetz commutator; spyglasses with scale for reading measuring instruments (Fig. 3); apparatus for the study of magnetic variations, of Lamont (Fig. 3) and of Wild (Fig. 5); different types of the Wiedemann galvanometer; an electrometer for atmospheric observations (Fig. 6); a dropping apparatus (Fig. 7), in which the iron ball opens one current at a time at the moment it leaves the electro-magnet and when it reaches the foot of the support, these two breakages producing two induction sparks that exactly limit the length to be taken in order to measure the time upon the tracing of the chronoscope tuning-fork; an absolute galvanometer; a bifilar galvanometer (Fig. 8) for absolute measurements, in which the helix is carried by two vertical steel wires stretched from o to u, and which is rendered complete by a mirror for the reading, and a second and fixed helix, so that an electro-dynamometer may be made of it; and, finally, a galvanometer for strong currents, having a horseshoe magnet pivoted upon a vertically divided column which is traversed by the current, and a plug that may be arranged at different heights between the two parts of the column so as to render the apparatus more sensitive (Fig. 9).



We may likewise cite the exhibit of Mr. Eugene Hartmann of Wurtzburg, which comprised a series of apparatus of the same class as those that we have just enumerated—spyglasses for the reading of apparatus, galvanometers, magnetometers, etc.



Specially worthy of remark were the apparatus of Mr. Kohlrausch for measuring resistances by means of induction currents, and a whole series of accessory instruments.

Among the objects shown by other exhibitors must be mentioned Prof. Von Waltenhofen's differential electromagnetic balance. In this, two iron cylinders are suspended from the extremities of a balance. One of them is of solid iron, and the other is of thin sheet iron and of larger diameter and is balanced by an additional weight. Both of them enter, up to their center, two solenoids. If a strong current be passed into these latter, the solid cylinder will be attracted; but if, on the contrary, the current be weak, the hollow cylinder will be attracted. If the change in the current's intensity occur gradually, there will be a moment in which the cylinders will remain in equilibrium.



Prof. Zenger's differential photometer that we shall finally cite is an improvement upon Bunsen's. In the latter the position of the observer's eye not being fixed, the aspect of the spot changes accordingly, and errors are liable to result therefrom. Besides, because of the non-parallelism of the luminous rays, each of the two surfaces is not lighted equally, and hence again there may occur divergences. In order to avoid such inconveniences, Prof. Zenger gives his apparatus (Fig. 10) the following form: The screen, D, is contained in a cubical box capable of receiving, through apertures, light from sources placed upon the two rules, R and R'. A flaring tube, P, fixes the position of the eye very definitely. As for the screen, this is painted with black varnish, and three vertical windows, about an inch apart, are left in white upon its paper. Over one of the halves of these parts a solution of stearine is passed. To operate with the apparatus, in comparing two lights, the central spot is first brought to invisibility, and the distances of the sources are measured. A second determination is at once made by causing one of the two other spots to disappear, and the mean of the two results is then taken. As, at a maximum, there is a difference corresponding to 3/100 of a candle between the illumination of the two neighboring windows, in the given conditions of the apparatus, the error is thus limited to a half of this value, or 2 per cent. of that of one candle.



Among the apparatus designed for demonstration in lecture courses, we remarked a solenoid of Prof. Von Beetz for demonstrating the constitution of magnets (Fig. 11), and in which eight magnetized needles, carrying mica disks painted half white and half black, move under the influence of the currents that are traversing the solenoid, or of magnets that are bought near to it externally. Another apparatus of the same inventor is the lecture-course galvanometer (Fig. 3), in which the horizontal needle bends back vertically over the external surface of a cylinder that carries divisions that are plainly visible to spectators at a distance.



Finally, let us cite an instrument designed for demonstrating the principle of the Gramme machine. A circular magnet, AA', is inserted into a bobbin, B, divided into two parts, and moves under the influence of a disk, L, actuated by a winch, M. This system permits of studying the currents developed in each portion of the bobbin during the revolution of the ring (Fig. 12).



To end our review of the scientific apparatus at the exhibition we shall merely mention Mr. Van Rysselberghe's registering thermometrograph (shown in Figs. 13 and 14), and shall then say a few words concerning two types of registering apparatus—Mr. Harlacher's water-current register and Prof. Von Beetz's chronograph.



Mr. Harlacher's apparatus was devised by him for studying the deep currents of the Elbe. It is carried (Fig. 15) by a long, vertical, hollow rod which is plunged into the river. A cord that passes over a pulley, P, allows of the apparatus, properly so called, being let down to a certain depth in the water. What is registered is the velocity of the vanes that are set in action by the current, and to effect such registry each revolution of the helix produces in the box, C, an electric contact that closes the circuit in the cable, F, attached to the terminals, B. This cable forms part of a circuit that includes a pile and a registering apparatus that is seen at L, outside of the box in which it is usually inclosed. In certain cases, a bell whose sound indicates the velocity of the current to the ear is substituted for the registering apparatus.



Fig. 16 represents another type of the same apparatus in which the mechanism of the contact is uncovered. The supporting rod is likewise in this type utilized as a current conductor.



It now remains to say a few words about Prof. Von Beetz's chronograph. This instrument (Fig. 17) is designed for determining the duration of combustion of different powders, the velocity of projectiles, etc. The registering drum, T, is revolved by hand through a winch, L, and the time is inscribed thereon by an electric tuning fork, S, set in motion by the large electro-magnet, E F. Each undulation of the curves corresponds to a hundredth of a second. The tuning-fork and the registering electro-magnets, G and H, are placed upon a regulatable support, C, by means of which they may be given any position desired.



The style, c, of the magnet, C, traces a point every second in order to facilitate the reading. The style, b, of the electro-magnet, H, registers the beginning and end of the phenomena that are being studied.



The apparatus is arranged in such a way that indications may thus be obtained upon the drum by means of induction sparks jumping between the style and the surface of the cylinder. To the left of the figure is seen the apparatus constructed by Lieutenant Ziegler for experimenting on the duration of combustion of bomb fuses.



Shortly after the drum has commenced revolving, the contact, K, opens a current which supports the heavy armature, P, of an electro-magnet, M. This weight, P, falls upon the rod, d, and inflames the fuse, Z, at that very instant. At this precise moment the electro-magnet, H, inscribes a point, and renews it only when the cartridge at the extremity of the fuse explodes.



This apparatus perhaps offers the inconvenience that the drum must be revolved by hand, and it would certainly be more convenient could it be put in movement at different velocities by means of a clockwork movement that would merely have to be thrown into gear at the desired moment. As it is, however, it presents valuable qualities, and, although it has already been employed in Germany for some time, it will be called upon to render still more extensive services.



We have now exhausted the subject of the apparatus of precision that were comprised in the Munich Exhibition. In general, it may be said that this class of instruments was very well represented there as regards numbers, and, on another hand, the manufacturers are to be congratulated for the care bestowed on their construction.—La Lumiere Electrique.



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COPPER VOLTAMETER.

Dr. Hammerl, of the Vienna Academy of Sciences, has made some experiments upon the disturbing influences on the correct indications of a copper voltameter. He investigated the effects of the intensity of the current, the distance apart of the plates, and their preparation before weighing. The main conclusion which he arrives at is this: That in order that the deposit should be proportional to the intensity of the current, the latter ought not to exceed seven amperes per square decimeter of area of the cathode.

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Speaking of steel ropes as transmitters of power, Professor Osborne Reynolds says these have a great advantage over shafts, for the stress on the section will be uniform, the velocity will be uniform, and may be at least ten to fifteen times as great as with shafts—say 100 ft. per second; the rope is carried on friction pulleys, which may be at distances 500 ft. or 600 ft. so that the coefficient of friction will not be more than 0.015, instead of 0.04.

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A NEW OXIDE OF COPPER BATTERY.

By MM. F. DE LALANDE and G. CHAPERON.

We have succeeded in forming a new battery with a single liquid and with a solid depolarizing element by associating oxide of copper, caustic potash, and zinc.

This battery possesses remarkable properties. Depolarizing electrodes are easily formed of oxide of copper. It is enough to keep it in contact with a plate or a cell of iron or copper constituting the positive pole of the element.

Fig. 1 represents a very simple arrangement. At the bottom of a glass jar, V, we place a box of sheet iron, A, containing oxide of copper, B. To this box is attached a copper wire insulated from the zinc by a piece of India rubber tube. The zinc is formed of a thick wire of this metal coiled in the form of a flat spiral, D, and suspended from a cover, E, which carries a terminal, F, connected with the zinc; an India-rubber tube, G, covers the zinc at the place where it dips into the liquid, to prevent its being eaten away at this level.

The jar is filled with a solution containing 30 or 40 per cent. of potash. This arrangement is similar to that of a Callaud element, with this difference—that the depolarizing element is solid and insoluble.



To prevent the inconveniences of the manipulation of the potash, we inclose a quantity of this substance in the solid state necessary for an element in the box which receives the oxide of copper, and furnish it with a cover supported by a ring of caoutchouc. It suffices then for working the battery to open the box of potash, to place it at the bottom of the jar, and to add water to dissolve the potash; we then pour in the copper oxide inclosed in a bag.

We also form the oxide of copper very conveniently into blocks. Among the various means which might be employed, we prefer the following:

We mix with the oxide of copper oxychloride of magnesium in the form of paste so as to convert the whole into a thick mass, which we introduce into metal boxes.

The mass sets in a short time, or very rapidly by the action of heat, and gives porous blocks of a solidity increasing with the quantity of cement employed (5 to 10 per cent.).



Fig. 2 represents an arrangement with blocks. The jar V, is provided with a cover of copper, E, screwing into the glass. This cover carries two vertical plates of sheet-iron, A, A', against which are fixed the prismatic blocks, B, B, by means of India rubber bands. The terminal, C, carried by the cover constitutes the positive pole. The zinc is formed of a single pencil, D, passing into a tube fixed to the center of the cover. The India rubber, G, is folded back upon this tube so as to make an air-tight joint.

The cover carries, besides, another tube, H, covered by a split India-rubber tube, which forms a safety valve.

The closing is made hermetical by means of an India rubber tube, K, which presses against the glass and the cover. The potash to charge the element is in pieces, and is contained either in the glass jar itself or in a separate box of sheet-iron.

Applying the same arrangement, we form hermetically sealed elements with a single plate of a very small size.

The employment of cells of iron, cast-iron, or copper, which are not attacked by the exciting liquid, allows us to easily construct elements exposing a large surface (Fig. 3).



The cell, A, forming the positive pole of the battery is of iron plate brazed upon vertical supports; it is 40 centimeters long by 20 centimeters wide, and about 10 centimeters high.

We cover the bottom with a layer of oxide of copper, and place in the four corners porcelain insulators, L, which support a horizontal plate of zinc, D, D', raised at one end and kept at a distance from the oxide of copper and from the metal walls of the cell; three-quarters of this is filled with a solution of potash. The terminals, C and M, fixed respectively to the iron cell and to the zinc, serve to attach the leading wires. To avoid the too rapid absorption of the carbonic acid of the air by the large exposed surface, we cover it with a thin layer of heavy petroleum (a substance uninflammable and without smell), or better still, we furnish the battery with a cover. These elements are easily packed so as to occupy little space.

We shall not discuss further the arrangements which may be varied infinitely, but point out the principal properties of the oxide of copper, zinc, and potash battery. As a battery with a solid depolarizing element, the new battery presents the advantage of only consuming its element, in proportion to its working; amalgamated zinc and copper are, in fact, not attacked by the alkaline solution, it is, therefore, durable.

Its electromotive force is very nearly one volt. Its internal resistance is very low. We may estimate it at 1/3 or 1/4 of an ohm for polar surfaces one decimeter square, separated by a distance of five centimeters.

The rendering of these couples is considerable; the small cells shown in Figs. 1 and 2 give about two amperes in short circuit; the large one gives 16 to 20 amperes. Two of these elements can replace a large Bunsen cell. They are remarkably constant. We may say that with a depolarizing surface double that of the zinc the battery will work without notable polarization, and almost until completely exhausted, even under the most unfavorable conditions. The transformation of the products, the change of the alkali into an alkaline salt of zinc, does not perceptibly vary the internal resistance. This great constancy is chiefly due to the progressive reduction of the depolarizing electrode to the state of very conductive metal, which augments its conductivity and its depolarizing power.

The peroxide of manganese, which forms the base of an excellent battery for giving a small rendering, possesses at first better conductivity than oxide of copper, but this property is lost by reduction and transformation into lower oxides. It follows that the copper battery will give a very large quantity of electricity working through low resistances, while under these conditions manganese batteries are rapidly polarized.

The energy contained in an oxide of copper and potash battery is very great, and far superior to that stored by an accumulator of the same weight, but the rendering is much less rapid. Potash may be employed in concentrated solution at 30, 40, 60 per cent.; solid potash can dissolve the oxide of zinc furnished by a weight of zinc more than one-third of its own weight. The quantity of oxide of copper to be employed exceeds by nearly one-quarter the weight of zinc which enters into action. These data allow of the reduction of the necessary substances to a very small relative weight.

The oxide of copper batteries have given interesting results in their application to telephones. For theatrical purposes the same battery may be employed during the whole performance, instead of four or five batteries. Their durability is considerable; three elements will work continuously, night and day, Edison's carbon microphones for more than four months without sensible loss of power.

Our elements will work for a hundred hours through low resistances, and can be worked at any moment, after several months, for example. It is only necessary to protect them by a cover from the action of the carbonic acid of the atmosphere.

We prefer potash to soda for ordinary batteries, notwithstanding its price and its higher equivalent, because it does not produce, like soda, creeping salts. Various modes of regeneration render this battery very economical. The deposited copper absorbs oxygen pretty readily by simple exposure to damp air, and can be used again. An oxidizing flame produces the same result very rapidly.

Lastly, by treating the exhausted battery as an accumulator, that is to say, by passing a current through it in the opposite direction, we restore the various products to their original condition; the copper absorbs oxygen, and the alkali is restored, while the zinc is deposited; but the spongy state of the deposited zinc necessitates its being submitted to a process, or to its being received upon a mercury support. Again, the oxide of copper which we employ, being a waste product of brazing and plate works, unless it be reduced, loses nothing of its value by its reduction in the battery; the depolarization may therefore be considered as costing scarcely anything. The oxide of copper battery is a durable and valuable battery, which by its special properties seems likely to replace advantageously in a great number of applications the batteries at present in use.

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FARCOT'S SIX HORSE POWER STEAM ENGINE.

This horizontal steam engine, recently constructed by Mr. E.D. Farcot for actuating a Cance dynamo-electric machine, consists of a cast iron bed frame, A, upon which are mounted all the parts. The two jacketed, cylinders, B and C, of different diameters, each contains a simple-acting piston. The two pistons are connected by one rod in common, which is fixed at its extremity to a cross-head, D, running in slides, E and F, and is connected with the connecting rod, G. The head of the latter is provided with a bearing of large diameter which embraces the journal of the driving shaft, H.

The steam enters the valve-box through the orifice, J, which is provided with a throttle-valve, L, that is connected with a governor placed upon the large cylinder. The steam, as shown in Fig. 2 (which represents the piston at one end of its travel), is first admitted against the right surface of the small piston, which it causes to effect an entire stroke corresponding to a half-revolution of the fly-wheel. The stroke completed, the slide-valve, actuated by an eccentric keyed to the driving shaft, returns backward and puts the cylinders, B and C, in communication. The steam then expands and drives the large piston to the right, so as to effect the second half of the fly-wheel's revolution. The exhaust occurs through the valve chamber, which, at each stroke, puts the large cylinder in connection with the eduction port, M.

The volume of air included between the two pistons is displaced at every stroke, so that, according to the position occupied by the pistons, it is held either by the large or small cylinder. The necessary result of this is that a compression of the air, and consequently a resistance, is brought about. In order to obviate this inconvenience, the constructor has connected the space between the two pistons at the part, A', of the frame by a bent pipe. The air, being alternately driven into and sucked out of this chamber, A', of relatively large dimensions, no longer produces but an insignificant resistance.



As shown in Fig. 5, there may be applied to this engine a variable expansion of the Farcot type. The motor being a single acting one, a single valve-plate suffices. This latter is, during its travel, arrested at one end by a stop and at the other by a cam actuated by the governor. Upon the axis of this cam there is keyed a gear wheel, with an endless screw, which permits of regulating it by hand.

This engine, which runs at a pressure of from 5 to 6 kilogrammes, makes 150 revolutions per minute and weighs 2,000 kilogrammes. —Annales Industrielles.

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FOOT LATHES.

We illustrate a foot lathe constructed by the Britannia Manufacturing Company, of Colchester, and specially designed for use on board ships. These lathes, says Engineering, are treble geared, in order that work which cannot usually be done without steam power may be accomplished by foot. For instance, they will turn a 24 inch wheel or plate, or take a half-inch cut off a 3 inch shaft, much heavier work than can ordinarily be done by such tools. They have 6 inch centers, gaps 71/2 inches wide and 61/2 inches deep, beds 4 feet 6 inches long by 83/4 inches on the face and 6 inches in depth, and weigh 14 cwt. There are three speeds on the cone pulley, 9 inches, 6 inches, and 4 inches in diameter and 11/2 inches wide. The gear wheels are 9/16 inch pitch and 11/2 inches wide on face. The steel leading screw is 11/2 inches in diameter by 1/4 inch pitch. Smaller sizes are made for torpedo boats and for places where space is limited.



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ENDLESS TROUGH CONVEYER.



The endless trough conveyer is one of the latest applications of link-belting, consisting primarily of a heavy chain belt carried over a pair of wheels, and in the intermediate space a truck on which the train runs. This chain or belt is provided with pans which, as they overlap, form an endless trough. Power being applied to revolve one of the wheels, the whole belt is thereby set in motion and at once becomes an endless trough conveyer. The accompanying engraving illustrates a section of this conveyer. A few of the pans are removed, to show the construction of the links; and above this a link and coupler are shown on a larger scale. As will be seen, the link is provided with wings, to form a rigid support for the pan to be riveted to it. To reduce friction each link is provided with three rollers, as will be seen in the engraving. This outfit makes a fireproof conveyer which will handle hot ore from roasting kiln to crusher, and convey coal, broken stone, or other gritty and coarse material. The Link Belt Machinery Company, of Chicago, is now erecting for Mr. Charles E. Coffin, of Muirkirk, Md., about 450 ft. of this conveyer, which is to carry the hot roasted iron ore from the kilns on an incline of about one foot in twelve up to the crusher. This dispenses with the barrow-men, and at an expenditure of a few more horsepower becomes a faithful servant, ready for work in all weather and at all times of day or night. This company also manufactures ore elevators of any capacity, which, used in connection with this apparatus, will handle perfectly anything in the shape of coarse, gritty material. It might be added that the endless trough conveyer is no experiment. Although comparatively new in this country, the American Engineering and Mining Journal says it has been in successful operation for some time in England, the English manufacturers of link-belting having had great success with it.



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RAILROAD GRADES OF TRUNK LINES.

On the West Shore and Buffalo road its limit of grade is 30 feet to the mile going west and north, and 20 feet to the mile going east and south. Next for easy grades comes the New York Central and Hudson River road. From New York to Albany, then up the valley of the Mohawk, till it gradually reaches the elevation of Lake Erie, it is all the time within the 500 foot level, and this is maintained by its connections on the lake borders to Chicago, by the "Nickel Plate," the Lake Shore and Michigan Southern, and the Canada Southern and Michigan Central.

The Erie, the Pennsylvania, and the Baltimore and Ohio roads pass through a country so mountainous that, much as they have expended to improve their grades, it is practically impossible for them to attain the easy grades so much more readily obtained by the trunk lines following the great natural waterways originally extending almost from Chicago to New York.

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ENGLISH EXPRESS TRAINS.

The Journal of the Statistical Society for September contains an elaborate paper by Mr. E. Foxwell on "English Express Trains; their Average Speed, etc. with Notes on Gradients, Long Runs, etc." The author takes great pains to explain his definition of the term "express trains," which he finally classifies thus: (a) The general rule; those which run under ordinary conditions, and attain a journey-speed of 40 and upward. These are about 85 per cent. of the whole. (b) Equally good trains, which, running against exceptional difficulties, only attain, perhaps, a journey speed as low as 36 or 37. These are about 5 per cent. of the whole. (c) Trains which should come under (a), but which, through unusually long stoppages or similar causes, only reach a journey speed of 39. These are about 10 per cent.[1] of the whole.

[Footnote 1: 10 per cent. of the number, but not of the mileage, of the whole; for most of this class run short journeys.]

He next explains that by "running average" is meant: The average speed per hour while actually in motion from platform to platform, i.e., the average speed obtained by deducting stoppages. Thus the 9-hour (up) Great Northern "Scotchman" stops 49 minutes on its journey from Edinburgh to King's Cross, and occupies 8 hours 11 minutes in actual motion; its "running average" is therefore 48 miles an hour, or, briefly, "r.a.=48." The statement for this train will thus appear: Distance in miles between Edinburgh and King's Cross, 3921/2; time, 9 h. 0 m.; journey-speed, 43.6; minutes stopped, 49; running average, 48.

Mr. Foxwell then proceeds to describe in detail the performances of the express trains of the leading English and Scottish railways—in Ireland there are no trains which come under his definition of "express"—giving the times of journey, the journey-speeds, minutes stopped on way, and running averages, with the gradients and other circumstances bearing on these performances. He sums up the results for the United Kingdom, omitting fractions, as follows:

========================================================================= Extent of Average System Distinct Journey- Running Express in Miles. Expresses. speed. Average. Mileage. -+ -+ -+ + -+ -+ 1773 North-Western {54} 82 40 43 10,400 {28} 1260 Midland 66 41 45 8,860 928 Great Northern {48} 67 43 46 6,780 {19} 907 Great Eastern 34 41 43 3,040 2267 Great Western 18 42 46 2,600 1519 North-Eastern 19 40 43 2,110 290 Manch., Sheffield, 49 43 44 2,318 and Lincoln 767 Caledonian 16 40 42 1,155 435 Brighton 13 41 41 1,155 382 South-Eastern 12 41 41 940 329 Glasgow and 8 41 43 920 South-Western 796 London and 3 41 44 890 South-Western 984 North British 11 39 41 830 153 Chatham and Dover 9 42 43 690 + -+ + -+ -+ 407 41 44 42,683 =========================================================================

A total of 407 express trains, whose average journey-speed is 41.6, and which run 42,680 miles at an average "running average" of 44.3 miles per hour.

If we arrange the companies according to their speed instead of their mileage, the order is:

Average r.a. Miles Great Northern. 46 6,780 Great Western. 46 [2]2,600 Midland. 45 8,860 Manchester, Sheffield, and Lincoln 44 2,318 London and South-Western. 44 890 North-Western. 43 10,400 Glasgow and South-Western. 43 920 Great Eastern. 43 3,040 North-Eastern. 43 2,110 Chatham and Dover. 43 690 Caledonian. 42 1,155 South-Eastern. 41 940 Brighton. 41 1,155 North British. 31 825

[Footnote 2: Not reckoning mileage west of Exeter.]

EXPRESS ROUTES ARRANGED IN ORDER OF DIFFICULTY OF GRADIENTS, ETC.

North British, Caledonian, Manch., Sheffield & Lincoln, Midland, Glasgow and South-Western, Chatham and Dover, South-Eastern, Great Northern, South-Western, Great Eastern, Brighton, North-Western, North-Eastern, Great Western.

LONG RUNS IN ENGLAND.

======================================================================= Number of Average Running Trains. Speed. Averages. - - Miles. Miles. Midland. 104 53 46 (5,512) North-Western. 98 60 45 (5,880) Great Northern. 49 73 50 (3,616) Great Western. 24 56 48 (1,344) Great Eastern. 24 56 42 (1,362) Brighton. 23 45 42 (1,047) North-Eastern. 20 56 44 (1,120) South-Western. 13 47 44 (615) South-Eastern. 12 66 42 (795) Chatham and Dover. 8 63 45 (504) Caledonian. 8 59 45 (476) Glasgow and South-Western 8 58 44 (468) Manchester, Sheffield, and Lincoln. 8 48 43 (390) North British. 7 60 40 (423) - - Total. 406 58 45 (23,550) =======================================================================

From this it will be seen that the three great companies run 61 per cent. of the whole express mileage, and 62 per cent. of the whole number of long runs.

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IMPROVED OIL MILL.

The old and cumbersome methods of crushing oil seeds by mechanical means have during the last few years undergone a complete revolution. By the old process, the seed, having been flattened between a pair of stones, was afterward ground by edge stones, weighing in some cases as much as 20 tons, and working at about eighteen revolutions per minute. Having been sufficiently ground, the seed was taken to a kettle or steam jacketed vessel, where it was heated, and thence drawn—in quantities sufficient for a cake—in woollen bags, which were placed in a hydraulic press. From four to six bags was the utmost that could be got into the press at one time, and the cakes were pressed between wrappers of horsehair on similar material. All this involved a good deal of manual labor, a cumberstone plant, and a considerable expense in the frequent replacing of the horsehair wrappers, each of which involved a cost of about L4. The modern requirements of trade have in every branch of industry ruthlessly compelled the abandonment of the slow, easy-going methods which satisfied the times when competition was less keen. Automatic mechanical arrangements, almost at every turn, more effectually and at greatly increased speed, complete manufacturing operations previously performed by hand, and oil-seed crushing machinery has been no exception to the general rule. The illustrations we give represent the latest developments in improved oil-mill machinery introduced by Rose, Downs & Thompson, named the "Colonial" mill, and recently we had an opportunity of inspecting the machinery complete before shipment to Calcutta, where it is being sent for the approaching exhibition. As compared with the old system of oil-seed crushing, Messrs. Rose, Downs & Thompson claim for their method, among other advantages, a great saving in driving power, economy of space, a more perfect extraction of the oil, an improved branding of the cakes, a saving of 50 per cent. in the labor employed in the press-room, with also a great saving in wear and tear, while the process is equally applicable to linseed, cottonseed, rapeseed, or similar seeds. In addition to these improvements in the system, the "Colonial" mill has been specially designed in structural arrangement to meet the requirements of exporters. The machinery and engine are self-contained on an iron foundation, so that there is no need of skilled mechanics to erect the mill, nor of expensive stone foundations, while the building covering the mill can, if desired, be of the lightest possible description, as no wall support is required. The mill consists of the following machinery: A vertical steel boiler, 3 ft. 7 in. diameter, 8 ft. 11/2 in. high, with three cross tubes 71/2 in. diameter, shell 5/16 in. thick, crown 3/8 in. thick, uptake 9 in. diameter, with all necessary fittings, and where wood fuel is used extra grate area can be provided. This boiler supplies the steam not only for the engine, but also for heating and damping the seed in the kettle. The engine is vertical, with 8 in. cylinder and 12 in. stroke, with high speed governors, and stands on the cast iron bed-plate of the mill. This bed-plate, which is in three sections, is about 30 ft. long, and is planed and shaped to receive the various machines, which, when the top is leveled, can be fixed in their respective places by any intelligent man, and when the machines are in position they form a support for the shafting. The seed to be crushed is stored in a wooden bin, placed above and behind the roll frame hopper. The roll frame has four chilled cast iron rolls, 15 in. face, 12 in. diameter, so arranged as to subject the seed to three rollings, with patent pressure giving apparatus. These rolls are driven by fast and loose pulleys by the shaft above. After the last rolling the seed falls through an opening in the foundation plate in a screen driven from the bottom roll shaft by a belt. This conveys the seed in a trough to a set of elevators, which supply it continuously to the kettle. This kettle, which is 3 ft. 6 in. internal diameter and 20 in. deep, is made of cast iron and of specially strong construction. There is only one steam joint in it, and to reduce the liability of leakage this joint is faced in a lathe. The inside furnishings of the kettle are a damping apparatus with perforated boss, upright shaft, stirrer, and delivery plate, and patent slide. The kettle body is fitted with a wood frame and covered with felt, which is inclosed within iron sheeting. The crushed seed is heated in the kettle to the required temperature by steam from the boiler, and it is also damped by a jet of steam which is regulated by a wheel valve with indicating plate. When the required temperature has been obtained, the seed is withdrawn by a measuring box through a self-acting shuttle in the kettle bottom, and evenly distributed over a strip of bagging supported on a steel tray in a Virtue patent moulding machine, where it undergoes a compression sufficient to reduce it to the size that can be taken in by the presses, but not sufficient to cause any extraction of the oil. The seed leaves the moulding machine in the form of a thick cake from nine to eleven pounds in weight, and each press is constructed to take in twelve of these cakes at once. The press cylinders are 12 in. diameter and are of crucible cast steel. To insure strength of construction and even distribution of strain throughout the press, all the columns, cylinders, rams, and heads are planed and turned accurately to gauges, and the pockets that take the columns, in the place of being cast, as is sometimes usual, with fitting strips top and bottom, are solid throughout, and are planed or slotted out of the solid to gauges. The pressure is given by a set of hydraulic pumps made of crucible cast steel and bored out of the solid. One of the pump rams is 21/2 in. diameter, and has a stroke of 7 in. This ram gives only a limited pressure, and the arrangements are such as to obtain this pressure upon each press in about fourteen seconds. This pump then automatically ceases running, and the work is taken up by a second plunger, having a ram 1 in. diameter and stroke of 7 in., the second pump continuing its work until a gross pressure of two tons per square inch is attained, which is the maximum, and is arrived at in less than two minutes. For shutting off the communication between the presses, the stop valves are so arranged that either press may be let down, or set to work without in the smallest degree affecting the other. The oil from the presses is caught in an oil tank behind, from which an oil pump, worked by an eccentric, forces it in any desired direction. The cakes, on being withdrawn from the press, are stripped of the bagging and cut to size in a specially arranged paring machine, which is placed off the bed-plate behind the kettle, and is driven by the pulley shown on the main shaft. The paring machine is also fitted with an arrangement for reducing the parings to meal, which is returned to the kettle, and again made up into cakes. The presses shown have corrugated press plates of Messrs. Rose, Downs & Thompson's latest type, but the cakes produced by this process can have any desired name or brand in block letters put upon them. The edges on the upper plate, it may be added, are found of great use in crushing some classes of green or moist seed. The plant, of which we give illustrations opposite, is constructed to crush about four tons of seed per day of eleven hours, and the manual labor has been so reduced to a minimum that it is intended to be worked by one man, who moulds and puts the twenty-four cakes into the presses, and while they are under pressure is engaged paring the cakes that have been previously pressed. In crushing castor-oil seed, a decorticating machine or separator can be combined with the mill, but in such a case the engine and boiler would require to be made larger.—The Engineer.



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APPARATUS FOR SEPARATING SUBSTANCES CONTAINED IN THE WASTE WATERS OF PAPER MILLS, ETC.

For extracting such useful materials as are contained in the waste waters of paper mills, cloth manufactories, etc., and, at the same time, for purifying such waters, Mr. Schuricht, of Siebenlehn, employs a sort of filter like that shown in the annexed Figs. 1 and 2, and underneath which he effects a vacuum.



The apparatus, A, is divided into two compartments, which are separated by a longitudinal partition. Above the stationary bottom, a, there is arranged a lattice-work grating or a strong wire cloth, b, upon which rests the filtering material, c, properly so called. The reservoir is divided transversely by several partitions, d, of different heights. The liquor entering through the leader, f, traverses the apparatus slowly, as a consequence of the somewhat wide section of the layer. But, in order that it may traverse the filtering material, it is necessary that, in addition to this horizontal motion, it shall have a downward one. As far as to the top of the partitions, d, there form in front of the latter certain layers which do not participate in the horizontal motion, but which can only move downward, as a consequence of the permeability of the bottom. It results from this that the heaviest solid particles deposit in the first compartment, while the others run over the first partition, d, and fall into one of the succeeding compartments, according to their degree of fineness, while the clarified water makes its exit through the spout, g. When the filtering layer, c, has become gradually impermeable, the cock, i, of a jet apparatus, k, is opened, in order to suck out the clarified water through the pipe, r.—Dingler's Polytech. Journ., after Bull. Musee de l'Industrie.



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LARGE BLUE PRINTS.

By W.B. PARSONS, JR., C.E.

I send you a description of a device that I got up for the N.Y., L.E., and W.R.R. division office at Port Jervis, by which I overcame the difficulties incident to large glasses. The glass was 58 inches long, 84 inches wide, and 3/8 inch thick. It was heavily framed with ash. In order to keep the back from warping out of shape, I had it made of thoroughly seasoned ash strips 1" x 1". Each strip was carefully planed, and then they were glued and screwed together, while across the ends were fastened strips with their grain running transversely. This back was then covered on side next to the glass with four thicknesses of common gray blanketing. Instead of applying the holding pressure by thumb cleats at the periphery, it was effected by two long pressure strips running across the back placed at about one quarter the length of the frame from the ends, and held by a screw at the center. The ends of these strips were made so as to fit in slots in the frame at a slight angle, so that as the pressure strips were turned it gave them a binding pressure at the same time. In other words, it is the same principle as is commonly used to keep backs in small picture frames. This arrangement, instead of holding the back at the edges only, and so allowing the center to fall away from the glass, distributed it evenly over the whole surface and always kept it in position. The frame was run in and out of the printing room on a little railway on which it rested on four grooved brass sheaves, one pair being at one end, while the other was just beyond the center, so the frame could be revolved in direction of its length without trouble. In order to raise the heavy back, I had a pulley-wheel fastened to the ceiling, through which a rope passed, with a ring that could be attached to a corresponding hook at the side of the back, in order to hoist it or lower it. Although that is an extremely large apparatus, yet by means of the above device it was worked easily and rapidly, and gave every satisfaction.

The solution used was of the same proportions as had been adopted in the other engineering offices of the road:

Citrate iron and ammonium 1-7/8 oz. Red prussiate potash (C.P.) 1-1/4 oz.

Dissolve separately in 4 oz. distilled water each, and mix when ready to use. But by putting mixture in dark bottle, and that in a tight box impervious to light, it can be kept two or three weeks.

In some frames used at the School of Mines for making large blue prints a similar device has been in use for several years. Instead, however, of the heavy and cumbrous back used by Mr. Parsons, a light, somewhat flexible back of one-quarter inch pine is employed, covered with heavy Canton flannel and several thicknesses of newspaper. The pressure is applied by light pressure strips of ash somewhat thicker at the middle than at the ends, which give a fairly uniform pressure across the width of the frame sufficient to hold the back firmly against the glass at all points. This system has been used with success for frames twenty-seven by forty-two inches, about half as large as the one described by Mr. Parsons. A frame of this size can be easily handled without mechanical aids. Care should be taken to avoid too great thickness and too much spring in the pressure strips, or the plate glass may be broken by excessive pressure. The strips used are about five-eighths of an inch thick at the middle, and taper to about three-eighths of an inch at the ends.

The formulae for the solution given by Whittaker, Laudy, and Parsons are practically identical so far as the proportions of citrate of iron and ammonia and of red prussiate of potash, 3 of the former to 2 of the latter, but differ in the amount of water. Laudy's formula calls for about 5 parts of water to 1 of the salts, Whittaker's for 4 parts, and Parson's for a little more than 2 parts. The stronger the solution the longer the exposure required. With very strong solutions a large portion of the Prussian blue formed comes off in the washwater, and when printing from glass negatives the fine lines and lighter tints are apt to suffer. The blue color, however, will be deep and the whites clear. With weak solutions the blues will be fainter and the whites bluish. Heavily sized paper gives the best results. The addition of a little mucilage to the solution is sometimes an advantage, producing the same results as strength of solution, by increasing the amount adhering to the paper. With paper deficient in sizing the mucilage also makes the whites clearer.—H.S.M., Sch. of M. Quarterly.

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HOUSE DRAINAGE AND REFUSE.

A course of lectures on sanitary engineering has been delivered during the past few weeks before the officers of the Royal Engineers stationed at Chatham, by Captain Douglas Galton, C.B., D.C.L., F.R.S.

The refuse which has to be dealt with, observed Captain Galton, whether in towns or in barracks or in camp, falls under the following five heads: 1, ashes; 2, kitchen refuse; 3, stable manure; 4, solid or liquid ejections; and 5, rainwater and domestic waste water, including water from personal ablutions, kitchen washing up, washings of passages, stables, yards, and pavements. In a camp you have the simplest form of dealing with these matters. The water supply is limited. Waste water and liquid ejection are absorbed by the ground; but a camp unprovided with latrines would always be in a state of danger from epidemic disease. One of the most frequent causes of an unhealthy condition of the air of a camp in former times has been either neglecting to provide latrines, so that the ground outside the camp becomes covered with filth, or constructing the latrines too shallow, and exposing too large a surface to rain, sun, and air. The Quartermaster-General's regulations provide against these contingencies; but I may as well here recapitulate the general principles which govern camp latrines. Latrines should be so managed that no smell from them should ever reach the men's tents. To insure this very simple precautions only are required:

1. The latrines should be placed to leeward with respect to prevailing winds, and at as great a distance from the tents as is compatible with convenience. 2. They should be dug narrow and deep, and their contents covered over every evening with at least a foot of fresh earth. A certain bulk and thickness of earth are required to absorb the putrescent gas, otherwise it will disperse itself and pollute the air to a considerable distance round. 3. When the latrine is filled to within 2 ft. 6 in. or 3 ft. of the surface, earth should be thrown into it, and heaped over it like a grave to mark its site. 4. Great care should be taken not to place latrines near existing wells, nor to dig wells near where latrines have been placed. The necessity of these precautions to prevent wells becoming polluted is obvious. Screens made out of any available material are, of course, required for latrines. This arrangement applies to a temporary camp, and is only admissible under such conditions.

A deep trench saves labor, and places the refuse in the most immediately safe position, but a buried mass of refuse will take a long time to decay; it should not be disturbed, and will taint the adjacent soil for a long time. This is of less consequence in a merely temporary encampment, while it might entail serious evils in localities continuously inhabited. The following plan of trench has been adopted as a more permanent arrangement in Indian villages, with the object of checking the frightful evil of surface pollution of the whole country, from the people habitually fouling the fields, roads, streets, and watercourses. Long trenches are dug, at about one foot or less in depth, at a spot set apart, about 200 or 300 yards from dwellings. Matting screens are placed round for decency. Each day the trench, which has received the excreta of the preceding day, is filled up, the excreta being covered with fresh earth obtained by digging a new trench adjoining, which, when it has been used, is treated in the same manner. Thus the trenches are gradually extended, until sufficient ground has been utilized, when they are plowed up and the site used for cultivation. The Indian plow does not penetrate more than eight inches; consequently, if the trench is too deep, the lower stratum is left unmixed with earth, forming a permanent cesspool, and becomes a source of future trouble. It is to be observed, however, that in the wet season these trenches cannot be used, and in sandy soil they do not answer. This system, although it is preferable to what formerly prevailed—viz., the surface defilement of the ground all round villages and of the adjacent water courses—is fraught with danger unless subsequent cultivation of the site be strictly enforced, because it would otherwise retain large and increasing masses of putrefying matter in the soil, in a condition somewhat unfavorable to rapid absorption. These arrangements are applicable only to very rough life or very poor communities.

The question of the removal of kitchen refuse, manure, etc., from barracks next calls for notice. The great principle to be observed in removing the solid refuse from barracks is that every decomposable substance should be taken away at once. This principle applies especially in warm climates. Even the daily removal of refuse entails the necessity of places for the deposit of the refuse, and therefore this principle must be applied in various ways to suit local convenience. In open situations, exposed to cool winds, there is less danger of injury to health from decomposing matters than there would be in hot, moist, or close positions. In the country generally there is less risk of injury than in close parts of towns. These considerations show that the same stringency is not necessarily required everywhere. Position by itself affords a certain degree of protection from nuisance. The amount of decomposing matter usually produced is also another point to be considered. A small daily product is not, of course, so injurious as a large product. Even the manner of accumulating decomposing substances influences their effect on health. There is less risk from a dung heap to the leeward than to the windward of a barrack. The receptacles in which refuse is temporarily placed, such as ash pits and manure pits, should never be below the level of the ground. If a deep pit is dug in the ground, into which the refuse is thrown in the intervals between times of removal, rain and surface water will mix with the refuse and hasten its decomposition, and generally the lowest part of the filth will not be removed, but will be left to fester and produce malaria. In all places where the occupation is permanent the following conditions should be attended to:

1. That the places of deposit be sufficiently removed from inhabited buildings to prevent any smell being perceived by the occupants. 2. That the places of deposit be above the level of the ground—never dug out of the ground. The floor of the ash pit or dung pit should be at least six inches above the surface level. 3. That the floor be paved with square sets, or flagged and drained. 4. That ash pits be covered. 5. That a space should be paved in front, so as to provide that the traffic which takes place in depositing the refuse or in removing it shall not produce a polluted surface.

In towns those parts of the refuse which cannot be utilized for manure or otherwise are burned. But this is an operation which, if done unskillfully, without a properly constructed kiln, may give rise to nuisance. One of the best forms of kiln is one now in operation at Ealing, which could be easily visited from London.

The removal of excreta from houses.—The chief object of a perfect system of house drainage is the immediate and complete removal from the house of all foul and effete matter directly it is produced. The first object—viz., removal of foul matter, can be attained either by the water closet system, when carried out in this integrity; but it could, of course, be attained without drains if there was labor enough always available; and the earth closet or the pail system are modifications of immediate removal which are safe. Cesspools in a house do not fulfill this condition of immediate removal. They serve for the retention of excremental and other matters. In a porous soil it endangers the purity of the wells. The Indian cities afford numerous examples of subsoil pollution. The Delhi ulcer was traced to the pollution of the wells from the contaminated subsoil; and the soil in many cities and villages is loaded with niter and salt, the chemical results of animal and vegetable refuse left to decay for many generations, from the presence of which the well water is impure. There are many factories of saltpeter in India whose supplies are derived from this source; and during the great French wars, when England blockaded all the seaports of Europe, the First Napoleon obtained saltpeter for gunpowder from the cesspits in Paris. Cesspools are inadmissible where complete removal can be effected. Cesspits may, however, be a necessity in some special cases, as, for instance, in detached houses or a small detached barrack. Where they cannot be avoided, the following conditions as to their use should be enforced:

1st. A cesspit should never be located under a dwelling. It should be placed outside, and as far removed from the immediate neighborhood of the dwelling as circumstances will allow. There should be a ventilated trap placed on the pipe leading from the watercloset to the cesspit. 2d. It should be formed of impervious material so as to permit of no leakage. 3d. It should be ventilated. 4th. No overflow should be permitted from it. 5th. When full it should be thoroughly emptied and cleaned out; for the matter left at the bottom of a cesspit is liable to be in a highly putrescible condition.

Where a cesspit is unavoidable, perhaps the best and least offensive system for emptying it is the pneumatic system. This is applicable to the water closet refuse alone. The pneumatic system acts as follows: A large air-tight cylinder on wheels, or, what answers equally, a series of air-tight barrels connected together by tubes about 3 in. diameter, placed on a cart, brought as near to the cesspit as is convenient; a tube of about the same diameter is led from them to the cesspit; the air is then exhausted in the barrels or cylinder either by means of an air pump or by means of steam injected into it, which, on condensation, forms a vacuum; and the contents of the cesspit are drawn through the tube by the atmospheric pressure into the cylinder or barrels. A plan which is practically an extension of this system has been introduced by Captain Liernur in Holland. He removes the faecal matter from water closets and the sedimentary production of kitchen sinks by pneumatic agency. He places large air-tight tanks in a suitable part of the town, to which he leads pipes from all houses. He creates a vacuum in the tanks, and thus sucks into one center the faecal matter from all the houses. Various substitutes have been tried for the cesspit, which retain the principle of the hand removal of excreta. The first was the combination of the privy with an ashpit above the surface of the ground, the ashes and excreta being mixed together, and both being removed periodically. The next improvement was the provision of a movable receptacle. Of this type the simplest arrangement is a box placed under the seat, which is taken out, the contents emptied into the scavenger's cart, and the box replaced. The difficulty of cleansing the angles of the boxes led to the adoption of oval or round pails. The pail is placed under the seat, and removed at stated intervals, or when full, and replaced by a clean pail. In Marseilles and Nice a somewhat similar system is in use. They employ cylindrical metal vessels furnished with a lid which closes hermetically, each capable of holding 11 gallons. The household is furnished with three or four of these vessels, and when one is full the lid is closed hermetically, the vessel thus remaining in a harmless condition in the house till taken away by the authorities and replaced by a clean one. The contents are converted into manure. In consequence of the offensiveness of the open pail, the next improvement was to throw in some form of deodorizing material daily. In the north of England the arrangement generally is that the ashes shall be passed through a shoot, on which they are sifted—the finer fall into the pail to deodorize it, the coarser pass into a box, whence they can be taken to be again burned—while a separate shoot is provided for kitchen refuse, which falls into another pail adjacent.

Probably the best known contrivance for deodorizing the excreta is the dry earth system as applied in the earth closet, in which advantage is taken of the deodorizing properties of earth. Dry earth is a good deodorizer; 11/2 lb. of dry earth of good garden ground or clay will deodorize such excretion. A larger quantity is required of sand or gravel. If the earth after use is dried, it can be applied again, and it is stated that the deodorizing powers of earth are not destroyed until it has been used ten or twelve times. This system requires close attention, or the dry earth closet will get out of order; as compared with water closets, it is cheaper in first construction, and is not liable to injury by frost; and it has this advantage over any form of cesspit—that it necessitates the daily removal of refuse. The cost of the dry earth system per 1,000 persons may be assumed as follows: Cost of closet, say, L500; expense of ovens, carts, horses, etc., L250; total capital, L750, at 6 per cent. L37 10s. interest. Wages of two men and a boy per week, L1 12s.; keep of horses, stables, etc., 18s.; fuel for drying earth, 1s. 6d. per ton dried daily, L1 10s.; cost of earth and repairs, etc., 14s.; weekly expenses, L4 14s. Yearly expenses, L247 (equal to 4s. 11d. per ton per annum); interest, L37 10s.—total, L284 10s., against which should be put the value of the manure. But the value of the manure is simply a question of carriage. If the manure is highly concentrated, like guano, it can stand a high carriage. If the manuring elements are diffused through a large bulk of passive substances, the cost of the carriage of the extra, or non-manuring, elements absorbs all profit. If a town, therefore, by adding deodorants to the contents of pails produces a large quantity of manure, containing much besides the actual manuring elements—such as is generally the case with dry earth—as soon as the districts immediately around have been fully supplied, a point is soon reached at which it is impossible to continue to find purchasers. The dry earth system is applicable to separate houses, or to institutions where much attention can be given to it, but it is inapplicable to large towns from the practical difficulties connected with procuring, carting, and storing the dry earth.

With the idea that if the solid part of the excreta could be separated from the liquid and kept comparatively dry the offensiveness would be much diminished, and deodorization be unnecessary, a method for getting rid of the liquid portion by what is termed the Goux system has been in use at Halifax. This system consists in lining the pail with a composition formed from the ashes and all the dry refuse which can be conveniently collected, together with some clay to give it adhesion. The lining is adjusted and kept in position by a means of a core or mould, which is allowed to remain in the pails until just before they are about to be placed under the seat; the core is then withdrawn, and the pail is left ready for use. The liquid which passes into the pail soaks into this lining, which thus forms the deodorizing medium. The proportion of absorbents in a lining 3 in. thick to the central space in a tub of the above dimensions would be about two to one; but unless the absorbents are dry, this proportion would be insufficient to produce a dry mass in the tubs when used for a week, and experience has shown that after being in use for several days the absorbing power of the lining is already exceeded, and the whole contents have remained liquid. There would appear to be little gain by the use of the Goux lining as regards freedom from nuisance, and though it removes the risk of splashing and does away with much of the unsightliness of the contents, the absorbent, inasmuch as it adds extra weight which has to be carried to and from the houses, is rather a disadvantage than otherwise from the manurial point of view.

The simple pail system, which is in use in various ways in the northern towns of England, and in the permanent camps to some extent at least, and of which the French "tinette" is an improved form, is more economically convenient than the dry earth system or the Goux or other deodorizing system, where a large amount of removal of refuse has to be accomplished, because by the pail system the liquid and solid ejections may be collected with a very small, or even without any, admixture of foreign substances; and, according to theory, the manurial value of dejections per head per annum ought to be from 8s. to 10s. The great superiority, in a sanitary point of view, of all the pail or pan systems over the best forms over the old cesspits or even the middens is due to the fact that the interval of collection is reduced to a minimum, the changing or emptying of the receptacles being sometimes effected daily, and the period never exceeding a week. The excrementitious matter is removed without soaking in the ground or putrefying in the midst of a population.

These plans for the removal of excreta do not deal with the equally important refuse liquid—viz., the waste water from washing and stables, etc. As it is necessary to have drains for the purpose of removing the waste water, it is more economical to allow this waste water to carry away the excreta. In any case, you must have drains for removing the fouled water. Down these drains it is evident that much of the liquid excreta will be poured, and thus you must take precautions to prevent the gases of decomposition which the drains are liable to contain from passing into your houses.

There is a method which you might find useful on a small scale to which I will now draw your attention, as it is applicable to detached houses or small barracks—viz., the plan of applying the domestic water to land through underground drains, or what is called subsoil irrigation. This system affords peculiar facilities for disposing of sewage matter without nuisance. There are many cases where open irrigation in close contiguity to mansions or dwellings might be exceedingly objectionable, and in such cases subsoil irrigation supplies a means of dealing with a very difficult question. This system was applied some years ago by Mr. Waring in Newport, in the United States. It has recently been introduced into this country.

The system is briefly as follows: The water from the house is carried through a water-tight drain to the ground where the irrigation is to be applied. It is there passed through ordinary drain pipes, placed 1 ft. below the surface, with open joints, by means of which it percolates into the soil. Land drains, 4 ft. deep, should be laid intermediately between the subsoil drains to remove the water from the soil. The difficulty of subsoil irrigation is to prevent deposit, which chokes the drains; and if the foul domestic water is allowed to trickle through the drains as it passes away from the house it soon chokes the drains. It is, therefore, necessary to pass it in flushes through the drains, and this can be best managed by running the water from the house into one of Field's automatic flush tanks, which runs off in a body when full.

When you have water closet and drainage, the great object to be attained in house drainage is to prevent the sewer gas from passing from the main sewer into the house drain. It was the custom to place a flap at the junction of the house drain with the sewer; but this flap is useless for preventing sewer gas from passing up the house drain. The plan was therefore adopted of placing a water trap under the water closet basin or the sink, etc., in direct communication with the drain. The capacity of water to absorb sewer gas is very great, consequently the water in the trap would absorb this gas. When the water became warm from increase of temperature, it would give out the gas into the house; when it cooled down at night, it would again absorb more gas from the soil pipe, and frequent change of temperature would cause it to give out and reabsorb the gas continually.

These objections have led to the present recognized system—viz., 1st, to place a water trap on the drain to cut off the sewer gases from the foot of the soil pipe; and, next, to place an opening to the outer air on the soil pipe between the trap and the house to secure efficient disconnection between the sewer and the house. It is, moreover, necessary to produce a movement of air and ventilation in the house drain pipes to aerate the pipe and to oxidize any putrescible products which may be in it. To do this, we must insure that a current of air shall be continually passing through the drains; both an inlet and an outlet for fresh air must be provided in the portions of the house drain which are cut off from the main sewer, for without an inlet and outlet there can be no efficient ventilation. This outlet and inlet can be obtained in the following manner: In the first place, an outlet may be formed by prolonging the soil pipe at its full diameter, and with an open top to above the roof, in a position away from the windows, skylights, or chimneys. And, secondly, an inlet may be obtained by an opening into the house drain, on the dwelling side of and close to the trap, by means of the disconnecting manhole or branch-pipe before mentioned, or where necessary by carrying up the inlet by means of a ventilating pipe to above the roof. The inlet should be equal in area to the drain pipe, and not in any case less than 4 in. in diameter. If it were not for appearance and the difficulty of conveying the excreta without lodgments, an open gutter would be preferable to a closed pipe in the house. This arrangement is based on the principle that there should be no deposit in the house drains. Therefore the utmost care should be taken to lay the house drains in straight lines, both in plan and gradient, and to give the adequate inclination.

The following are desirable conditions to observe in house drains: 1. As to material of pipes. House drains should be made either of glazed stoneware pipes or fireclay pipes with cement joints, or preferably of cast iron pipes jointed with carefully-made lead joints, or with turned joints and bored sockets. I say preferably of cast iron. In New York the iron soilpipe, with joints made with lead, is now required by the municipal regulations. It is a stronger pipe than a rainwater pipe. The latter will often be found to have holes. A lead joint cannot be made properly in a weak pipe, therefore the lead joint is to some extent a guarantee of soundness. Lead pipes will be eaten away by water containing free oxygen without carbonic acid, therefore pure rainwater injures lead pipes. An excess of carbonic acid in water will also eat away lead. You will find that in many cases pinholes appear in a soilpipe, and when inside a house that allows sewer gas to pass into the house. Moreover, lead is a soft material; it is subject to indentations, to injury from nails, to sagging. A cast-iron pipe, when coated with sewage matter, does not appear to be subject to decay; and if of sufficient substance it is not liable to injury. When once well fixed, it has no tendency to move. I would, therefore, advocate cast iron in lieu of lead soilpipes. In fixing the soilpipe which is to receive a water-closet, the trap should form part of the fixed pipe; so that if there is any sinking the down pipe will not sink away from the trap. It is, however, not sufficient to provide good material. There is nothing which is more important in a sanitary point of view than good workmanship in house drainage. In this matter, it is on details that all depends. Just consider; the drain pipes under the best conditions of aeration contain elements of danger, and those pipes are composed of a number of parts, at the point of junction of any one of which the poison may escape into the house. You thus perceive how necessary it is first to reduce the poison to a minimum by cutting off the sewer gas which might otherwise pass from the street sewer to the house drain, and in the next place being most careful in the workmanship of every part of your house drains and soilpipes. Reduce your danger where you can by putting your pipes outside. But you cannot always do that—for instance, at New York and in Canada they would freeze.

All drain pipes should be proved to be watertight by plugging up the lower end of the drain pipe and filling it with water. In no case should a soilpipe be built inside a wall. It should be so placed as to be always accessible. 2. The pipes should be generally 4 in. diameter. In no instance need a drain pipe inside a house exceed 6 in. in diameter. 3. Every drain of a house or building should be laid with true gradients, in no case less than 1/100, but much steeper would be preferable. When from circumstances the drain is laid at a smaller inclination, a flush tank should be provided. They should be laid in straight lines from point to point. At every change of direction there should be reserved a means of access to the drain. 4. No drain should be constructed so as to pass under a dwelling house, except in particular cases when absolutely necessary. In such cases the pipe should be of cast iron, and the length of drain laid under the house should be laid perfectly straight—a means of access should be provided at each end; it should have a free air current passing through it from end to end, and a flush tank should be placed at the upper end. 5. Every house drain should be arranged so as to be flushed, and kept at all times free from deposit. 6. Every house drain should be ventilated by at least two suitable openings, one at each end, so as to afford a current of air through the drain, and no pipe or opening should be used for ventilation unless the same be carried upward without angles or horizontal lengths, and with tight joints. The size of such pipes or openings should be fully equal to that of the drain pipe ventilated. 7. The upper extremities of ventilating pipes should be at a distance from any windows or openings, so that there will be no danger of the escape of the foul air into the interior of the house from such pipes. The soilpipe should terminate at its lower end in a properly ventilating disconnecting trap, so that a current of air would be constantly maintained through the pipe. 8. No rainwater pipe and no overflow or waste pipe from any cistern or rainwater tank, or from any sink (other than a slop sink for urine), or from any bath or lavatory, should pass directly to the soilpipe; but every such pipe should be disconnected therefrom by passing through the wall to the outside of the house, and discharging with an end open to the air. I may mention here that the drainage arrangements of this Parkes Museum in which we are assembled were very defective when the building was first taken. Mr. Rogers Field, one of the committee, was requested to drain it properly, and it has been very successfully accomplished.

I would now draw your attention to some points of detail in the fittings for carrying away waste water.

First, with regard to lavatories. As already mentioned, every waste pipe from the sink should deliver in the open air, but it should have an opening at its upper end as well as at its lower end, to permit a current of air to pass through it; and it should be trapped close to the sink, so as to prevent the air being drawn through it into the house; otherwise you will have an offensive smell from it. I will give you an instance: At the University College Hospital there are some fire tanks on the several landings. The water flows in every day, and some flows away through the waste pipes; these pipes, which carry away nothing but fresh London water to empty in the yard, got most offensive simply from the decomposition of the sediment left in them by the London water passing through them day after day. A small waste pipe from a bath or a basin is a great inconvenience. It should be of a size to empty rapidly—for a bath 2 inches, a basin 11/2, inches. There are other points connected with fittings to which I would call your attention. The great inventive powers which have been applied to the w.c. pan are an evidence of how unsatisfactory they all are. Many kinds of water-closet apparatus and of so-called "traps" have a tendency to retain foul matter in the house, and therefore, in reality, partake more or less of the nature of small cesspools, and nuisances are frequently attributed to the ingress of "sewer gas" which have nothing whatever to do with the sewers, but arise from foul air generated in the house drains and internal fittings. The old form was always made with what is called a D-trap. Avoid the D-trap. It is simply a small cesspool which cannot be cleaned out. Any trap in which refuse remains is an objectionable cesspool. It is a receptacle for putrescrible matter. In a lead pipe your trap should always be smooth and without corners. The depth of dip of a trap should depend on the frequency of use of the trap. It varies from 1/2 inch to 31/2 inches. When a trap is rarely used, the dip should be deeper than when frequently used, to allow of evaporation. In the section of a w.c. pan, the object to be attained is to take that form in which all the parts of the trap can be easily examined and cleaned, in which both the pan and the trap will be washed clean by the water at each discharge, and in which the lever movement of the handle will not allow of the passage of sewer gas.

And now just a few personal remarks in conclusion. I have had much pleasure in giving to my old brother officers in these lectures the result of my experience in sanitary science. In doing so, I desired especially to impress on you who are just entering your profession the importance of giving effect to those principles of sanitary science which were left very much in abeyance until after the Crimean war. I have not desired to fetter you with dogmatic rules, but I have sought, by general illustrations, to show you the principles on which sanitary science rests. That science is embodied in the words, pure earth, pure air, pure water. In nature that purity is insured by increasing movement. Neither ought we to stagnate. In the application of these principles your goal of to-day should be your starting-post for to-morrow. If I have fulfilled my object, I shall have interested you sufficiently to induce some of you at least to seize and carry forward to a more advanced position the torch of sanitary science.

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PASTEUR'S NEW METHOD OF ATTENUATION.

The view that vaccinia is attenuated variola is well known, and has been extensively adopted by English physicians. If the opinion means anything, it signifies that the two diseases are in essence one and the same, differing only in degree. M. Pasteur has recently found that by passing the bacillus of "rouget" of pigs through rabbits, he can effect a considerable attenuation of the "rouget" virus. He has shown that rabbits inoculated with the bacillus of rouget become very ill and die, but if the inoculations be carried through a series of rabbits, a notable modification results in the bacillus. As regards the rabbits themselves, no favorable change occurs—they are all made very ill, or die. But if inoculation be made on pigs from those rabbits, at the end of the series it is found that the pigs have the disease in a mild form, and, moreover, that they enjoy immunity from further attacks of "rouget." This simply means that the rabbits have effected, or the bacillus has undergone while in them, an attenuation of virulence. So the pigs may be "vaccinated" with the modified virus, have the disease in a mild form, and thereafter be protected from the disease. The analogy between this process and the accepted view of vaccinia is very close. The variolous virus is believed to pass through the cow, and there to become attenuated, so that inoculations from the cow-pox no longer produce variola in the human subject, but cow-pox (vaccinia). As an allied process, though of very different result, mention may be made of some collateral experiments of Pasteur, also performed recently. Briefly, it has been discovered that the bacillus of the "rouget" of pigs undergoes an increase of virulence by being cultivated through a series of pigeons. Inoculations from the last of the series of pigeons give rise to a most intense form of the disease. It will be remembered that the discovery of the bacillus of "rouget" of pigs was due to the late Dr. Thuillier.—Lancet.

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Very few persons realize the necessity of cultivating an equable temper and of avoiding passion. Many persons have met with sudden death, the result of a weak heart and passionate nature.

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CONVENIENT VAULTS.

This is a subject which will bear line upon line and precept upon precept. Many persons have availed themselves of the cheap and easy means which we have formerly recommended in the shape of the daily use of absorbents, but a larger number strangely neglect these means, and foul air and impure drainage are followed by disease and death. Sifted coal ashes and road dust are the remedy, kept in barrels till needed for use. A neat cask, filled with these absorbents, with a long-handled dipper, is placed in the closet, and a conspicuous placard directs every occupant to throw down a dipper full before leaving. The vaults, made to open on the outside, are then as easily cleaned twice a year as sand is shoveled from a pit. No drainage by secret, underground seams in the soil can then poison the water of wells; and no effluvia can arise to taint the air and create fevers. On this account, this arrangement is safer and better than water-closets. It is far cheaper and simpler, and need never get out of order. There being no odor whatever, if properly attended to, it may be contiguous to the dwelling. An illustration of the way in which the latter is accomplished is shown by Fig. 1, which represents a neat addition to a kitchen wing, with hip-roof, the entrance being either from the kichen through an entry, or from the outside as shown by the steps. Fig. 2 is a plan, showing the double walls with interposed solid earth, to exclude any possible impurity from the cellar in case of neglect. The vaults may be reached from the outside opening, for removing the contents. In the whole arrangement there is not a vestige of impure air, and it is as neat as a parlor; and the man who cleans out the vaults say it is no more unpleasant than to shovel sand from a pit.



Those who prefer may place the closet at a short distance from the house, provided the walk is flanked on both sides with evergreen trees; for no person should be compelled to encounter drifting snows to reach it—an exposure often resulting in colds and sickness. A few dollars are the whole cost, and civilization and humanity demand as much.—Country Gentleman.



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POISONOUS SERPENTS AND THEIR VENOM.

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