even of science. It is a very fine instrument as large as a common piano; and beside it there are others so small that they may be taken in the arms.

The Thermogenic machine of Mayer and Beaumont is the object of unceasing curiosity; and it certainly is a remarkable fact that in this way, the simple friction of a piston of leather within a tube, making 300 turns of rotation in a minute, should furnish steam. The boiler is ordinarily under 2-horse pressure. It is actually put in use within the Crystal Palace, where it furnishes the hot water required for making coffee and chocolate. To produce the heat requisite for 2 horse power in the steam, requires at least 4 horse power. The inventors propose to use their machine only when it is convenient to utilise lost force. In the fine display, made by Nachet, there are the multiple microscopes, of which I have spoken.t

Duboscq has on exhibition his electric regulator; Edmond Becquerel, his apparatus for chromatic photography; M. Felix Bernard of Bordeaux, a refractometer and also an apparatus for determining the polarization of the atmosphere.

Duboscq shows also stereoscopes by reflection and refraction. The stereoscopic views are less successful than those in the English Department.

Among the articles from England, we observe with interest the apparatus employed by M. Tyndall in his researches on magnetic phenomena; also the electro-magnet employed by M. Faraday for diamagnetic phenomena, and for examining the effect of magnetism on polarized light; this electro-magnet is in the show-case of Ruhmkorff, where there is also a differential galvanometer of Weber, and Ruhmkorff's induction apparatus, which has proved of great service to amateurs in electricity. There is also a model of circular electro-magnets; another of trifurcate electro-magnets;|| the rheostat of Wheatstone, etc.

M. Froment exhibits many kinds of apparatus of great interest :-as writing telegraphs;-a telegraph with a finger-board;-the gyroscope of Foucault apparatus for determining the velocity of heat, light and electricity, which has had the approbation of Arago, Bréguet, Silbermann, Froment, Foucault, Fizeau, &c. He also exhibits an electro-magnetic machine, which it is true will not be found particularly useful, but is still interesting on account of the plan of its construction. It is a circle of brass carrying at intervals iron armatures. This circle is placed in a drum also of brass, but furnished with horseshoe electro-magnets. On putting the current in action each armature in turn is attracted; and thus the interior circle is put in motion and. acquires a velocity of rotation on itself, which is quite fatiguing in consequence of the shocks to which the circle is exposed.

In the French department, there are two other electro-magnetic machines: one moved by circular electro-magnets, the other with trifurcate magnets. Six circular electro-magnets with three poles are arranged on an axis. Around these electro-magnets, are arranged six cyl. indrical iron bars serving as armatures, and moveable upon their axes. *This Jour., September, 1855. Ib., Jan., 1855.

Ib., Jan., 1853.

Ib., Jan. and May, 1853.

Ib., January, 1853. Ib., March, 1853.

The circumference of the electro-magnets is at intervals terminated by brass plates so arranged as to serve to interrupt the magnetic circuit. As long as the iron portion of the circumference approaches the arma. ture, it tends to separate itself from it, and carries in its movement the whole mass of the electro-magnet with the axis which supports it and the fly-wheel on the latter; but at the moment when contact takes place, the current is interrupted and driven through the electro-magnet, in consequence of which the play just described is recommenced. The apparatus is neither powerful nor economical. It would be better to employ circular electro-magnets with two poles.

The electro-magnetic machine with trifurcate magnets is more pow erful, since the action between the magnet and armature is not exerted at the time of contact. But I may describe these machines at a future time with some details, and now add only that neither of them resolves the problem of an economical motor.

The only galvanic battery on exhibition, which has any novelty, is that called the electro-hydro-dynamic, by M. Chenot, in which he uses the sponge of iron, of which he is the discoverer, as already communicated. The same inventor has a machine which is an interesting application of electro-magnetism to the dressing of iron ores. These ores, being magnetic, are thus easily separated from the gangue and made ready for the furnace. The machine is a drum carrying electromagnets on its circumference. A screen carries the impure ore under the drum where the poles of the electro-magnets take up the oxyd of iron and leave the gangue on the frame to be transported by it into an enclosure one side. As the drum moves on in rotation, the galvanic fluid is made to leave the first range of magnets and act upon the next; the ore of the first is thus dropped, while the next is taking its load. M. Chenot thus uses with profit ores containing only 9 per cent. of oxyd of iron. Among the other applications which are on exhibition, not to speak of the magnificent galvanoplastic products, there are different systems of electric telegraph.

There is the signal telegraph of M. Bréguet, in which the same signals are made as sometimes used in the ordinary aerial telegraphing. It is in fact only a union of two telegraphs with ordinary dial plates; for if we suppose two of these telegraphs in action at the same time, and so arranged as to produce by their indicating needles whose extremities move over a black line drawn on the dial plate of the receiver, 8 positions in its turn in place of 26 which the alphabet requires, you will have some idea of the signal telegraph which has been adopted by the administration of telegraphic lines in France-adopted not without resisting progress for several years, and denying the benefits of the electric telegraph for a long period after this invention was employed in the United States.

M. Froment, exhibits a telegraph in which manipulation is through a box with a finger-board, having as many keys as letters. A arbor in this box tends constantly to move under a clock movement and carries in its motion the wheel which opens or closes the circuit; but it is retained by a catch which pressure on a key raises,—a simple arrangement for producing the breaks in the current. The receiver is that of the primitive telegraph.

The forms of telegraphic apparatus are numerous and interesting, though constructed on known principles. The more important are those of Froment, Bréguet, Garnier, in France, Berg and Soerrenden, of Sweden; the Company of the Eastern Railway, etc. The bell telegraph of Mirand has now many applications: its principle is that of Morse's telegraph.

Other examples of the application of electricity, are the Anemograph of Dumoncel, an instrument for measuring the direction, elevation, and force of the winds;* a heat regulator for hot-houses and drying chambers; and a system of electric communication between railroad trains.

M. Henley of London, has on exhibition a magneto-electric machine made of powerful magnets for springing mines. Deleuil, Breton, and Bekking of Holland, have induction apparatuses for medical uses. There is nothing especially remarkable in them.

The exposition contains also models of the submarine cables which have been used in connection with telegraphs, and of those which are soon to be laid down between Italy and Algiers.

In another communication, I propose to allude to other machines and chemical products and arts represented at the Crystal Palace.

Zoological Society of Acclimation. Project of founding a Museum of Applied and Comparative Natural History.-This zoological society continues its labors and with important results. Being essentially_pacific in its objects, it has entered into relations with the Imperial Economical Society of St. Petersburg, and established with that Society a system of exchanges of objects industrially useful.

This Russian Society has in view an end long since proposed for France by M. Guérin Meneville, that is to make a collection of all raw products raised and used in the country, and of specimens illustrating the series of transformations they undergo in the processes of the arts. It would include also objects injurious to the articles which man cultivates. In such a gallery, the agriculturist, the trader, and the practical man, will find whatever illustrates his own departments, and be able to make comparisons important to direct them in the various operations of the arts and trade.

The St. Petersburg Society has already made such a collection of the productions of Russia, and their transformations. It includes all kinds of wheat, from the grain to the flour, bran, and starch, &c., as well as models of machines employed in cultivation, &c., from the plough to the wind-mill and the implements of baking. So there is wool of various kinds, and the raw material, and all the tissues coarse and fine, &c.; and so with a multitude of objects, pertaining to the three kingdoms of nature.

The Zoological Society of Acclimation, not wishing to confine itself to the productions of France alone, has resolved to reserve the objects it may obtain by exchange for a "Muséum d'Histoire Naturelle appliquée et comparée," to contain the products of all countries so as to exhibit the differences between them.

Acclimation of the Angora goat.-The Society is trying to decide whether the Angora goat can be acclimated. At their request, they

* This Journal, September, 1853.

have recieved from Abd-el-Kader, at Broussa (Asia Minor) a flock of goats from Angora, fifteen in number, which have been sent to the mountains of the south, centre, and east of France. We have seen some of them in the enclosures for acclimation of Dr. Sace at Wesserling (Haut Rhin), a valley possessing much that is curious in its industry, and of interest in the remains of ancient glaciers still traceable there. Two kids have been born since the goats were sent to Alsace, and as yet there is nothing to show that acclimation is impossible. The orientals doubt the success, and say that the texture of the wool changes even for small distances in the same zone and the same region.

The region occupied by the Angora comprises a part of Central Galatia and a southwest portion of Paphlagonia, between the parallels of 39° 20′ and 41° 30', and the meridians of 33° 20′ and 35° east of Paris, the surface of which is about 2350 square metric leagues. The goat avoids the highest mountains, not ascending beyond 1600 meters, according to M. Tchihatcheff, who has studied the animal in Asia Minor. It also keeps out of the lower valleys where the heat is high in sunmer. The village of Angora is the place where this goat is raised with the most success and in largest numbers. Its altitude is about 1120 meters and its climate is liable to great extremes.

One of the most striking characteristics of the Angora goat, is its strong attachment to its native soil: a removal, however slight, causes a change in the quality of the wool. M. Tchihatcheff observes that all attempts to transfer it to Constantinople, Smyrna, and other parts of Asia Minor, have been without permanent success, the wool of the second generation beginning to deteriorate.

We may hope from the success experienced in other cases of acclimation, that Asia Minor is not the only place where the Angora may be made to live and flourish. The Egyptian goose was brought to France from Egypt in 1799 by Geoffroy, senior, and his son finally succeeded in acclimating it.

Since these trials with the Angora were begun, M. Graells, director of the Museum at Madrid, has stated that a flock of one hundred of these goals was introduced into Spain in 1830, and that there are now two hundred of them in the mountains of the Escurial, and still another flock in the mountainous region of Huelva.

Academy of Sciences.-The universal exposition at Paris has had some effect on the Academy of Sciences in bringing distinguished men from all parts of Europe and Britain to its meetings. At one recent session, there were present MM. Liebig, Brewster, Wheatstone, De la Rive, H. Rose, Poggendorff, Rammelsberg, Dove, Steinheil, etc. At this Scientific Congress, the United States is worthily represented by Mr. T. S. Hunt, of Canada, whose numerous confining occupations as a member of the Jury at the Crystal Palace, have hindered him from pursuing his scientific labors. He has made a series of communications to the Academy of Sciences, some of them treating on theoretical subjects of a profound character connected with great questions in philosophical chemistry now commencing to occupy the scientific world, and others specially on the geology of Canada.

Bibliographical Notices.-Astronomie Populaire, d'ARAGO, vol. ii, Paris: Gide and Baudry.-This volume is almost wholly devoted to the

Sun, the Zodiacal light and Comets. The theory on the physical constitution of the Sun; a careful essay on the Solar Spots; an examina. tion of the Zodiacal light; a very complete treatise on Comets, give great interest to this volume. The author discusses the question whether the Sun is inhabited, and treats of the magnetic effects of the Sun on the compass.

He also describes the parallactic stand, the equatorial and the rotating dome of the Paris Observatory, as also the Polariscope lens of his invention.

Etudes et Lectures sur les Sciences d'Observation et leurs applicacations pratiques, by M. BABINET, Member of the Institute. 1 vol., 12mo. Paris, Mallet Bachelier. Price 2 francs.-This work is intended for popular reading. It contains several lectures, some of which were delivered at the periodical sessions of the five Academies of the Institute. One is entitled Extraordinary Movements of the Sea; another, Comets in the nineteenth century; another, The Electric Telegraph, in which M. Babinet states that he does not believe in the possi bility of uniting Europe and America across the Atlantic Ocean, and thinks the course by Behring Straits the only one practicable; another, On Astronomy in 1852, 1853; Aerial Perspective; The Stereoscope and binocular vision; and finally it closes with an interesting chapter entitled " Voyage dans le ciel." M. Babinet, a relative and friend of Arago, understands how to throw into his lectures the same charm and simplicity that characterised the popular public addresses of Arago.

Etudes sur la géographie botanique de L'Europe et en particulier sur la végétation du plateau central de la France; by M. H. LECOQ, Professor of Botany in the Faculty of Sciences of Clermont. 4 vols., 8vo, with plates. Paris: Baillière.-The author, who has for thirty years been exploring the mountains of Auvergne and the central plateau of France, has been led to compare the facts observed there by himself with those recognised by him in other regions. No one understands Auvergne like M. Lecoq; to him all questions are referred relating to the geology of that country.

SCIENTIFIC INTELLIGENCE.

I. CHEMISTRY AND PHYSICS.

1. On the relations between the boiling points, specific volumes and chemical constitution of bodies.-Since the appearance of his remark. able paper on the specific volumes of fluids, already noticed in this Journal, Kopp has published an elaborate memoir on densities, dilatations, and boiling points, confining himself however to a statement of his numerical results. In a still later publication he gives a brief summary of his conclusions which will be interesting to all chemists. With reference to boiling points the author finds a great number of facts which go to confirm the laws previously discovered by himself and already widely known. In a great number of comparisons of similar fluid bodies, the differences between the specific volumes taken at the boiling