Chapter 1

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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. ARCHÆOLOGY.--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 ampères 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.