of the expedition, has been made a purser in the royal navy; and Mr. M'Diarmid, the surgeon, has been presented with a surgeoncy on board one of his Majesty's ships. Thus all parties concerned appear to have had their services liberally considered by the Government, although, from the expedition being of an entirely private character, they could have, strictly speaking, no claims on the public.

Saxon Science in the Land o' Cakes.-Active preparations are already on foot in Edinburgh for the reception of the "British Association for the Advancement of Science," whose fourth annual congress is to take place in the Scottish capital in September next. It is not probable, however, that it will be so splendid an affair as the two last meetings at Oxford and Cambridge; since, as a Scottish periodical hints, the learned bodies of "Auld Reekie" do not possess the control over funds so extensive as those of the great English universities: it is proposed, notwithstanding, for the honour of Caledonian hospitality, to give at least one dinner to the southern horde, and leave the pock-puddings" to their own discretion for the rest of their stay-except as regards food for the mind! The first meeting of the association, that at York, was held, as this is to be, in September, but those for 1832 and 1833 both took place in June.

Progress of Steam Navigation with India-A steam voyage from India to England, by the Red Sea, seems at last to be really on the eve of taking place. The steamer Forbes has been engaged to start from Calcutta for Suez in the beginning of the present month, the Hugh Lindsay having been pronounced unfit for the purpose. The whole expense, except that of the coals, is to be borne by the Indian Government; while the Calcutta Steam Navigation Committee, will receive all the profits on passengers and all kinds of freight, except letters, the postage of which will be reserved by the Government. Should the voyage succeed, the steamer may be hired for two more trips on the same terms. The fund is still increasing by subscriptions from every quarter, but, unfortunately, symptoms of dissension begin to appear between the Bombay and Calcutta committees, in consequence, it may be supposed, of its having been determined that the start shall be taken from the latter port, instead of the former, which had all along looked for the distinction.

The New Smithfield at Islington.-The opposi. tion to this concern has become so strong and so decided, that it is highly improbable the bill for enabling the proprietor to commence operations will find its way through Parliament. It is by no means unlikely, however, that the agitation of the question will induce the City to take some steps for the removal of the great cattle-market from the heart of the metropolis. The idea of attaching abattoirs, or slaughter-houses, to the new building, has been for some time abandoned.

The New South Wales Magazine.-The first number of this periodical has already reached England; it is crammed to the full with "local" matter, but betrays altogether what is too plainly the fact, that, although printed and published at Sydney, it is chiefly intended to find a sale in the London market." Almost every article-nay, even the very matter-bears about it a sort of consciousness of its being "got up" to produce a striking effect in the minds of the English, rather than the colonial public, which takes away mightily from the interest of the affair. Amongst the contributors is a Dr. Lhotsky, a Russian emigrant, who, we perceive, is now endeavouring, after delivering a course of lectures on geology and mineralogy, to better his fortunes by setting on foot a "Mine-exploring Association," for bringing to light the mineral treasures of Aus

tralia. Literature is by no means so cheap in New Holland as at home, if we may judge from the price of this magazine, which, although of a consumptive thinness, is charged at half-a-crown.

The Statistical Society.-Two meetings have been lately held for the establishment of a society for the collection and publication of statistical details; and a committee has been appointed to prepare the laws of the intended association. Such a society would undoubtedly be far from the least important, in its objects and the value of its la bours, of the learned bodies of the metropolis, numerons as they have become of late years. The plan does not lack influential supporters, if we may judge from the circumstance of the Marquis of Lansdown's taking the chair at the preliminary meeting, and addresses being delivered on the same occasion by Messrs. Goulburn, Spring Rice, &c. &c., as well as by the staunchest supporter, if not the originator, of the society, Dr. Jones, the new Professor of Political Economy at King's College. F. H.

"The description given in the Mechanics' Magazine, No. 554, of the Birmingham Town hall, requires several corrections. In the first place, Mr. Harris is not the architect; he was merely the publisher of a beautiful view of the buildingMessrs. Hansom and Welch were the architects; and they have been no further concerned at Liverpool than in the superintendence of a church. The fluted columns were not worked by machinery, as the description states-the whole was done by hand, except the sawing, which was done by an ingenious machine, the invention of Mr. Hansom, one of the architects-whose design, in fact, the whole building is. The columns, in the view, are only five diameters in height, whereas they ought to have been ten. Another defect is, that the basement is shown of regular masonry, whereas it is formed of the roughest blocks, called rough rustic." -GEO. GLOVER. 17, Gerrard-street, Soho, 29th April, 1834-We understand that some misunderstandings have unfortunately arisen between the committee for superintending the erection of the Town-hall and the contractors. The contract has, it is said, been broken, and the committee have, for some time past, had workmen of their own employed on the building, which cannot, however, be now completed within the time contemplated. The estimated expense will also be greatly exceeded.

A second number of the "Library of Popular Instruction has been left at our office, with a very pretty enamelled card, on which is engraved the name of "Dr. J. P. Litchfield," We gather from this that we were wrong, in hinting that the words "Edited by Dr. J. P. Litchfield" might cover a mere fiction of trade. What he is doctor of, however, we have yet to learn; and it must be confessed, that he takes rather a questionable method of putting forward his academical pretensions. Is he of Oxford, or Cambridge, or Edinburgh, or St. Andrews, or cannie Aberdeen? Is he LL.D., or D.C.L., or M.D., or Mus. D., or only (what his Library deserves to be) D- -D.?

Communications received from ..-Mr. Holmes-Northampton-Mr. Bayley-R. M. A.A Seeker-Mr. Baddeley-Mr. Landale-A SemiSnob.

Erratum.

Page 61, in the article by p. μ., for "Bannoscope" read" Baunoscope"-the principal root of the name being Bavvos, a furnace.

LONDON: Published by M. SALMON, at the Mechanics' Magazine Office, No. 6, Peterborough Court, between 135 and 136, Fleet-street. Agent for the American Edition, Mr. O. RICH, 12, Red Lion square. Sold by G. G. BENNIS, 55, Rue Neuve, Saint Augustin, Paris.

M. SALMON, Printer, Fleet-street,

114

DESCRIPTION OF A MAGNETO-ELECTRIC RING, EQUAL IN POWER TO THE LARGEST GALVANIC BATTERIES.

Sir-In my communication, which you havẹ dɔne me the honour to insert in No. 556, pige 6, I promised to send some of the heads of a paper, drawn up for Prof. Jameson's Journal of April last, in case it should have been too late for that quarter's number. I have since been informed that the paper was too late, but that it will appear in the coming July number of the Edinburgh Philosophical Journal. Meantime I proceed to redeem my promise, begging, in the first place, to trespass upon your patience with a few particulars, which the peculiar circumstances connected with my experiments render necessary. The data in my hands, on commencing, were the Treatises on Electricity and Magnetism published by the Useful Knowledge Society, and a common magneto-electric apparatus, with a bar armature. I had also seen, for a few minutes, a small magneto-electric apparatus, with a rotary arinature. What else had been done in this branch of electricity, since the date of the above-mentioned production, I was altogether uninformed of. By a series of experiments I was led to the discovery and construction of the magneto electric ring, and its auxiliary the galvanic reverser. As, however, I was aware that working entirely alone, and remote from any source of recent information, I must be only re-producing old inventions-an apprehension strengthened by the plain leading of the data to the consequences I had drawn from them-I immediately wrote to Dr. Roget, the author of the above-mentioned tracts, I communicated the heads of my invention, and begged to be informed, whether it really was as new as original. I had not the honour of an answer. I concluded that my letter must have miscarried, and took the liberty to apply in the next instance to Mr Faraday. I had the pleasure to receive a letter from Mr. Faraday, dated 14th April last, and was informed by that gentleman that such a ring as mine was constructed by him in 1831, and that from it was produced the very first magneto-electric spark. He referred me to a paper on the subject by him in the Philosophical Transactions for 1832, page 131. In order to follow up the reference, I was obliged to write to a

friend eighty miles off. He had the kindness, assisted by another, to tran scribe the paper in question, and I this day (May 10th) received the manuscript. On a perusal of Mr. Faraday's paper I find that he has, indeed, anticipated me in the discovery of the principle of the construction of the ring, and has followed out most of the principal ramifications in such a masterly style as his name would lead us to expect. I think, however, it will appear, that the practical importance of the ring has been overlooked, and not fully developedother and more dazzling results, seen beyond, attracted the philosopher's eye, and he passed on. I do not, therefore, sir, mean, although all my own deductions and experiments have been strictly origi nal, to interfere further with Mr. Faraday's clear claim to the discovery of the principle, and to the construction of the magneto-electric ring. The practical development of its almost unlimited powers may be allowed to be mine.

I shall now proceed to describe the apparatus, of which I have prefixed a sort of figure. The course of reasoning in my mind took this turn. I saw that the development of the magnet's electricity, by the rotary apparatus, had arrived at its maximum--the limit being imposed by the unwieldiness which the apparatus assumed when the effect was to be increased beyond a certain degree. It was apparent, also, that the maximum effects produced were comparatively feeble, and in some cases dubious. Permanent steel magnets did not appear essential, because the magnetism, which immediately excites the elecurity of the coils, is that of the armature. The remedy seemed, then, to consist in dispensing with the mediate agents, the steel magnets, in increasing the size of the armature, and in rendering both magnet and armature fixed. These conditions I effected by taking the iron ring, by making one segment serve as magnet and the other as armature, and by transterring the rotary motion to a separate auxiliary apparatus, the galvanic reverser. The magneto-electric ring may be constructed as follows:-The dimensions I state are those which I consider the maximum, consistently with convenience. It is scarcely worth while to stop short of the maximum, when magnificent results may be attained by a comparatively