The history of the railway from St. Petersburgh to Zarskoeselo and Pawlowsk, which is by this time in operation, presents several remarkable points of contrast with similar works in England, which throw considerable light on the relative situations of the two countries. In England, all the railways executed and projected have a view to the promotion of trade, or the public convenience. In Russia, this, their first railway, is composed of two branches, running from the capital, one to the imperial residence of Zarskoeselo, and the other to the middle of the park of the Grand Duke Michael. In England, the speculators would have had to go through an infinity of trouble and expense to procure an "Act"-in Russia all this roundabout process was avoided; as soon as the Emperor took the concern under his patronage, all difficulties vanished; an imperial ukase directed the immediate cession of all private lands on the line to the Company (compensation to be an after consideration), and conferred the privilege of carrying the railroad for a whole mile through [the most erowded streets of the metropolis, without troubling the "corporation of St. Petersburgh" for their consent. By the same means the Company were freed, for the first ten years, from what is here a pretty considerable nuisance-the payment of rates and taxes. The will of the Autocrat, however, was not sufficiently powerful to produce an effect which would have happened naturally enough in England-the manufacture of the railway and its appliances by "native talent." As a matter of course, the whole were imported from England; the rails from the Butterley and Bedlington Iron-works and the Welsh furnaces of Messrs. Guest, Lewis, and Co., and the pedestals from Butterley only. The locomotive-carriages were furnished by Mr. Stephenson, of Newcastle, Mr. Hackworth, of New Shildon, and Mr. Tayleur, of Warrington; their only foreign competitor, too, was foreign in residence alone-Mr. Cockerill, the English iron-master of Liege, in Belgium. Some of the English locomotives were tried on railways here before being shipped for their destination, and, if report can be relied on, went at the rate of 75 miles an hour! The only party not English about the concern appears to have been the chief engineer, Von Gerstner, a German-and he received his railway-education in this country, which he visited on purpose. Every article of mechanism required came ready-made from England :-the weighing-machines were supplied by Mr. Kitchen, of Warrington; a crane, by Sharp and Roberts, of Manchester; clocks, with illuminated dials (in the style of our first-rate gin-shops), by Mr. Paine, of London; and even the " trumpet-machines," which the Company are compelled to use, to give notice of the approach of their carriages when traversing the streets of St. Petersburgh, were manufactured in our own metropolis, by Messrs. Robson and Son. Each carriage is also provided with an apparatus (which will not be without its use in such a climate as that of Russia) for removing frozen sleet and snow from the rails. The railway is 18 miles in length, that is, the Pawlowsk branch, which was the first undertaken, It terminates in the centre of the Grand Duke's park, where the Company have erected a large building as a house of entertainment, their principal dependance for remuneration being on the holiday-makers of St. Petersburgh, who, they calculate, somewhat in the fashion of similar speculators nearer home, will pass along it at the rate of 1,500,000l. per annum, though their expectations of a profit of 13 per cent. on their capital of 3,000,000 rubles (135,000l.) are based on the supposition that no more than 300,000 will make use of their conveyances. At present it is reckoned that the number of horses employed in keeping up the communication is 178,187 in the year. The time required to perform the distance on the railway will be half an hour only, and the (lowest) fare half a ruble; while the diligence takes from two to three hours, and charges three rubles. The works were commenced in April, and the first line was expected to be finished in six or seven months, as, with the powerful patronage of the Czar, physical obstacles were the only ones that had to be encountered. PERPETUAL MOTION. Sir, I was much surprised, on looking through your 696th Number, to see that any one else should have been induced to make an attempt at perpetual motion on Mr. Mackintosh's plan, as shown at p. 149, when it must be plain to every one, that gravity, the very power which was intended to give motion to the wheel, is completely neutralised by the power of the magnet; and that the backward motion described by Mr. Mackintosh, and verified by Mr. Monro (see p. 192), proves nothing more than that the friction between the ball and the wheel was greater than the friction on the axle of the wheel. The suggestion of the ratchet, to prevent the said retrograde movement, was certainly good, as proved on its application by Mr. Monro; but I am at a loss to understand how any one having the slightest smattering of mechanical knowledge, could imagine it should have any tendency to reverse the only motion produced. But I should say, the most extraordinary part of the affair is, that a rational being could be led, by the failure of so futile an attempt, to conclude that gravity, in the hands of the great Creator, is insufficient to produce that, which he (Mr. Mackintosh) in his experiment had taken most effectual means to prevent. Yours, &c. TREBOR VALENTINE. PROPELLING VESSELS BY AIR-CLOCK ON A NEW PRINCIPLE. Sir,-Now that I am driven from my workshop (which is, in fact, a summerhouse, and very damp) by the severe weather, I cannot help taking my pen, as a substitute for more laborious employment, to tell of what I have been about the past summer. My first experiment was the method of propelling a boat I mentioned in my letter in No. 670 of the Mechanics' Magazine; and although the comparative velocity was small to what I have obtained by various kinds of paddle-wheels, I think the plan applicable to purposes of war and canals. To explainI made a boat, three feet long, seven inches wide, and placed in the fore part a pair of single bellows (they should be double) but I did not fit an air-vessel, as I ought to have done, so as to prevent the return of water up the vent-hole or bellows-pipe. To this I fitted a train of levers, cranks, and wheels, with a moderate clock-spring; the vent-hole passed at an angle of about 20° through the bottom of the boat, near the centre of gravity, and blew into an enclosed column of water, open a-head and a-stern. This produced motion, but instead of one venthole there should have been many, with a constant power like steam. What it may become is impossible to say, but I should like to try further. My next idea was a kind of clock different from any hitherto attempted, and so made as not to be affected by either temperature or humidity; and to prove this last idea, I made a hygrometer which involved the principle of my clock. I constructed a very delicate brass balance, with scale of degrees below; and on one end of the balance I put a disc of wood, painted, varnished, and double-gilt-on the other end I placed another disc of the same wood, quite plain. I then adjusted the balance parallel with the index of my whalebone hygrometer, four feet long, and they have ranged parallel ever since, only the balance is the most sensible of the two. My clock is made without pendulum or spring; in fact, I make the going-weight lift alternately a small Counter-weight attached to a beam at one end, and the pulley or the balance-wheel is fastened to the other end of the beam by means of a horse-hair. Balancewheel and pulley are of wood, painted, varnished, and double-gilt; the balance MANUFACTURE OF IRON. Sir, Is it not very surprising that a matter of such vital importance to the whole mechanical world as the manufac-" ture of iron should have been so little discussed in your pages?-certainly we had a very full account of the saving effected by the use of the hot-blast, anda which was broadly stated at the same time to improve the quality as well as the quantity of metal so manufactured; but it was also stated that the quality of the said metal was much deteriorated: now one of these statements must, of course, be untrue, and one of your correspondents, Mr. Glynn, of the Butterley Iron-Works, I think, volunteered to furnish some samples, by which the question was to have been decided by you. Nothing having transpired for so great a length of time, I beg leave to ask whether it arises from any remissness on your part? and, at the same time, once more to call the attention of all whom it may concern, with this additional fact, which can only be taken as an acknowledgment of the inferiority of hot-blast iron; viz. the holders of metal manufactured by the cold-blast, now regularly demand 20s. per ton extra for it. Yours respectfully, THE LAW OF BUILDING COMPANIES. [Building Companies are great favourites with mechanics-those of country towns especially and we think deservedly so. When prudently and honestly managed, they furnish great facilities for the conversion of the savings of industry into real estate. It cannot, therefore, be made too generally known, that by a recent statute the same legisla tive protection (nearly) has been wisely extended to all societies of this description, established prior to the 1st of June last, as is enjoyed by Friendly Societies. The following exposition of the new law on the subject we extract from Mr. Wordsworth's "Law of Joint Stock Companies" (2d Edition, 1837)-a most instructive and useful work, which no society or club of mechanics, associated for pecuniary objects, should be without. -ED. M.M.] "From the preamble of the statute* it appears, that certain societies, called Building Societies, have been established in different parts of the kingdom, principally amongst the industrious classes, for the purpose of raising, by small periodical sub. scriptions, a fund to assist the members thereof, in obtaining a small freehold or leasehold property. Accordingly, the Legislature have thought it expedient to afford encouragement and protection to such societies, and to the property obtained therewith. And they have enacted, that any number of persons may form themselves into societies for the purpose of raising a fund by monthly or other subscriptions of the several members. Shares not exceeding the value of 1501. for each share, such subscriptions not to exceed in the whole 20s. per month for each share. The object of this fund is to enable each member to erect or purchase a house; but the same is to be considered as mortgaged to the Company until the amount of the member's share shall have been fully repaid to such society with interest, &c. The members may assemble together and make such rules for their guidance as the majority may think proper, provided they are not repugnant to the present enactment, and the general laws of the realm. A power is given to inflict fines upon the members if they contravene the rules. It is prescribed that no interest or dividend shall be paid upon any shares, until the amount or value shall have been realised, except in the event of a member withdrawing himself.+ "The society may receive from its members money by way of bonus for the privilege of receiving the amount of value of the share prior to its being realised, and also the interest on such share so received, without being subject to the usury laws.‡ "The rules may prescribe forms of conveyance, mortgage, transfer, agreement, bond, or other instrument, provided the forms be inserted in a schedule to the rules, and duly certified and deposited.§ * 6 and 7 Will. IV., c. 32, App. p. 51. "The provisions of the Friendly Societies' Acts, 10 Geo. IV. c. 56, and 4 and 5 Will. IV. c. 40, are extended to this Act, so far as any part thereof may be applicable to building societies, and to the framing, certifying, enrolling, and altering the rules, in such and the same manner as if such Friendly Societies' Acts had been expressly enacted in the present statute.|| "The trustees named in any mortgage made on behalf of the society, may endorse thereon, or upon any other instrument given, a receipt for monies intended to be secured by such mortgage, &c., which shall be sufficient to vacate the same, and vest the estate in the property comprised in such security in the person, for the time being, entitled to the equity of redemption, thereby dispensing with the necessity of conveyance. ¶ "No building society can, however, vest any part of its funds in the Savings' Bank, or with the Commissioners for the reduction of the National Debt.** "Nor is any society entitled to the benefit of this enactment, unless its rules be certified and deposited as directed by the Friendly Societies' Acts.++ Finally, under the 8th section, an exemption is given from the operation of the Stamp Duties." CANAL IMPROVEMENTS. Sir,-In Number 672 of your truly valuable Journal, there is a scheme suggested by the Rev. Dr. Carey, of Clonmel, for working canal-locks, without any loss of water or rather a description of a new lock for that purpose, relative to which, with your permission, I will make one or two remarks. From the rather unintelligible description which is given of it, I suppose we cannot err by concluding, that the process consists of nothing less than raising the water from the lower to the upper level, by exhausting the air from the basin of the lock, by means of the sheet-iron chamber and air-pump there mentioned; in fact, pumping the water from one level into the other. If this conclusion be correct, I have not the least hesitation in pronouncing it a chimerical project altogether, and one which can never be rendered of the least practical use. For if we only consider the great extent of exhaustion which would be requisite, that of itself would be a sufficient objection; and the simple ques |