there was not the slightest irregularity in any part of the transaction. The Chancellor of the Exchequer fully acknow. ledged the right of inquiry, and should not therefore offer any objection to the production of the papers called for. The public are much indebted to Mr. Walter for bringing this affair under the notice of Parliament. We may now be pretty certain that, though the 30,000l. cannot be got back, there will be no more of the public money thrown away upon this desperate speculation. Mr. Hawes (who, besides being a Director of the Tunnel Company is related by marriage to Mr. Brunel), pretends that the 30,000l. was not advanced under any particular Act of Parliament in favour of the Company, but by the Commissioners for the Loan of Exchequer Bills on Public Works, in virtue of the general powers vested in them. It may be very convenient to give this turn to the matter, now that there is a noise made about it; but we suspect the Honourable Gentleman will find it rather difficult to make good his assertion. That an Act was smuggled through the House in the way described by Mr. Walter, authorising the Exchequer Bill Commissioners to advance 247,0007., is not denied. Why, then, should the 30,000l. have been advanced under the general powers vested in the Commissioners, rather than under this special Act for the purpose? Of what use was the special Act if it was not to be acted upon? It appears to us perfectly clear, from Mr. Walter's narrative, that both the Lords of the Treasury and the Exchequer Bill Commissioners supposed that they were, acting under the authority of the special Act. We must, also, take the liberty of reminding Mr. Hawes, that this was the version of the matter given by that gentleman himself and his brother Directors, at the time-though now they deem it more advisable to go upon another tack. On the 3d of March last, there: was an annual meeting held of the shareholders of the Tunnel Company, and the following is an extract of the proceedings as given in the Times of the 5th of March following: : "The Chairman said the Directors were pleased to meet the Proprietors under rather different circumstances than for the last seven years past, as the GOVERNMENT had placed in their hands a sum of money which the Company's engineers thought would be sufficient TO COMPLETE the tunnel. The advance had been made to the Company in Exchequer Bills, and they would, therefore, have the advantage of the premium. The Company were, under these circumstances, much indebted to the late Government, as well, indeed, as to the present, for this aid. Great credit was due to all those who had advocated the grant of money; and among those who had formed the deputation to Govern. ment were men of all parties. The time was not now far distant when it was confidently believed this magnificent work would be completed, and some return made to the Proprietors for the money they had advanced. "The Report of the Directors was then read, stating, that 247,000l in Exchequer Bills was to be advanced to the Company, on the security of their property." Not a word, the reader sees, of 30,000. only, or of " general powers," or any thing of the sort. The sum for which the Direc tors profess themselves to be everlastingly beholden to the Government is the identical 247,000l. authorised to be advanced for the completion of the work by that special Act which Mr. Hawes now affects to regard as a dead letter. The next time Mr. Walter moves in the matter, he should call for a copy of the Report which the Directors are stated, in the preceding extract, to have made to their constituents in March last. That would probably establish the real state of the case beyond all denial; and place, at the same time, the conduct of the patriotic Member for Lambeth in a light more to be lamented than envied. NOTES AND NOTICES. Cultivation of Silk in England -A company has been formed in Norwich for rearing silk-worms. They are possessed of 120,000 of these valuable insects, in a most healthy state, and have planted 1,000 mulberry trees for future provision. In the mean time contributions of mulberry leaves have been liberally afforded by many gentlemen who are desirous of encouraging the undertaking. Important Chemical Discoveries. We are requested by a learned Professor in Germany to invite the attention of our chemical manufacturers to the following valuable chemical discoveries:1. A new method of preparing white lead, by which a much finer and whiter article than the best Dutch or English white lead is produced in a great deal less time, and with much less labour. The advantage is, at least, equal to 40 per cent. The method is now in successful operation in three manufactories on the Continent, but is as yet unknown in England -2. A method of obtaining a vinegar from wood, equal to the best wine or table vinegar. -3. A printer's ink, of extraordinary purity and cheapness. And, 4. A method of preparing yeast' equal to the best yeast from malt or beer, at half the cost. The inventor is desirous of disposing of all or any one of these inventions; and will, if desired, forward specimens of the articles. Any communications on the subject, addressed to the care of the Editor, shall be duly forwarded. Communications received from A. R. W.-Q. Xanthine-H.-W. M. P.-Enort-R. F. A.Mr. Whitelaw. Errata.-P. 260, col. 2, 1. 44, after" 687 of the principal inhabitants" add "of Portland."-In the signature to Mr. Woodhouse's article on Angular Railways, p. 281, for "P. Woodhouse" read "Jas. Woodhouse." Patents taken out with economy and despatch; Specifications prepared or revised; Caveats entered; and generally every Branch of Patent Business promptly transacted. Drawings of Machinery also executed by skilful assistants, on the shortest notice. Our Publisher will give One Shilling and Sixpence for copies of the Supplement to Vol. IX. LONDON: Published by J. CUNNINGHAM, 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. CUNNINGHAM and SALMON, Printers, Fleet-street. SAILING AND ROWING TREBLE BOAT. Sir, I beg through the medium of your valuable journal to show to the public one way by which the principle of twin-boats may be applied, if not to any extent of usefulness, at least in making an addition to the recreations of amateurs in rowing and sailing, and, therefore, recommended to those who are fond of both. The plan in question has for its object to unite sailing and rowing, in the most convenient manner, so that any person or club possessing a rowing-boat of any description, from a twelve-oared galley to a wherry or skiff, may contrive to make a good sailing boat, and still have her in readiness for use as a rowing-boat, perfectly unencumbered with masts, sails, ballast, &c.; in fact, in the same state as if she had not been used for sailing. The proposed sketches will sufficiently elucidate my meaning, it being quite unnecessary to determine upon the shape, size, or dimensions, of the twin-boats, which may be formed to suit all fancies, for the attainment of whatever good quality they may be required to possess. Al AA are the twin-boats, which may be of such capacities and distances asunder as may be judged proper for stability. B is the row-boat, which is placed in the centre between the others, and secured to the beams by screws passing through them into her gunwales, or by their passing through the beams with screw nuts, or any other simple and convenient method, thus forming a treble-boat. though the central boat offers herself conveniently enough for housing the mast, I do not take advantage of it, because it would be a hindrance to using the boat with dispatch; besides, it is of little consequence, as owing to the great spread of the rigging, very little housing would be necessary, a wooden shock fixed to one of the beams, or a low thwart from one beam to the other, would answer every purpose. Fig. 2 shows how she may be rigged as a cutter, for instance, and she is represented as sailing directly before the wind, with her bowsprit, containing her fore-sail and jib spread over on the opposite side of her main-sail, which is made to revolve at its inner end C, fig. 1; and when the boat is sailing upon a wind, it is secured to the stern by a clamp, by which method the necessity of a square sail is avoided, a plan of this nature being manageable enough upon a small scale; however, as the rigging part has nothing to do with the first' intention of the plan, I leave that entirely to the judgment of the amateur. After the above explanation, it will be readily imagined that the central boat is always in a state of readiness, and when it is considered that the largest class of yacht cutters cannot conveniently stow a large galley, the convenience of the plan is obvious; by way of an example, I will suppose a club of gentlemen having a rowing galley, and being desirous of making a long excursion coastwise, or from one river to another, now instead of over-fatiguing themselves by rowing the whole of the distance, they might auchor the treble-boat in a place of security at the mouth of one river, and row up the other, which latter may be supposed to be too narrow for the treble-boat to work up, and the same reasoning would hold good for those who possessed Thames wherries or small skiffs. As the twin-boats would be decked out and made watertight, the sailing would be attended with the safety of a life-boat. When the treble-boats, too, were on such scale as to exceed the length of 25 feet, the twin boats would then be capacious enough for the accommodation of sleeping-berths, -small cabins, as their owners might think fit, properly shut in with hatch ways. I can recommend the plan the better from having tried it; therefore, an observation or two, as to how she works, may not be amiss. The display of good judgment all depends upon the distance of the twin-boats from each other, together with their capacities suiting whatever weight of mast, rigging, and quantity of convass it is proposed to give the boat. Should the twin-boats be of small capacities and too far asunder, the longitudinal stability or liability to turn over in sailing before the wind may be less than the lateral, or that required in sailing upon a wind; this is the point in which the stability differs so widely from single boats. I have read in some pub lication that it would be next to impossible for a twin-boat to be upset, but that is a fallacy, as any vessel may be masted and rigged in proportion to her stability, which I have learnt by experience for having so masted my treble-boat, as to oblige me to take in reefs when other vessels did, I was once all but upset; the lee boat was apparently entirely submerged, and it is clear that the maximum of stability must be in that situation, with the whole weight of the weatherboat suspended in the air,, when, if sail be not immediately reduced, a rapid cap size must follow, unlike to a well-ballasted boat which would be finding her equilibrium. It is true that a treble-boat may be under-masted for her stability and still answer every purpose, and then her comparatively superior stability would become her best coasting quality, and if with a moderate breeze she outsailed every other boat of her length, that would certainly be the most prudent course to adopt. I only mean to remark, that treble-boats similarly to single ones may be adapted either for safety, convenience, or racing, and that many good qualities are only attainable but at the expense of others. The experience which I gained with my treble-boat (14 feet only in length) was, that in sailing free or before the wind, she flew past every other boat, and she forereached and worked well to wind. ward, but did not hold a better wind than in common, which I ascribed to the circumstance of her stability having been gained by great breadth of beam with no weight of ballast, and, consequently, her presenting above the water-line so much more surface of hull than a well-ballasted single boat would have done; however, there is no determining upon the achievements of a boat of larger dimensions than mine. I had only two strong beams to unite my little treble-boats together; of course, longer boats would require more, but it is only on a large scale that it would be indispensable to resort to stronger combinations of unity, as diagonal trussing, &c. As it is advantageous to have the twin-boats a good depth, and, at the same time, a proper height out of the water, I should recommend to any person who may construct one upon a large scale, not to mind, should the height of the beams require the central boat to be lifted out of the water, or merely to skim upon the surface, when she is bolted to them, as she would not add much to the stability, but on a small scale she cannot so well be got rid of, and her services must not then be despised. Notwithstanding my having said that the present plan can only benefit the re creations of aquatic amateurs, that 1 might not appear to give it more importance than it merits, I think that it is one of the many of those plans which every naval officer should make himself ac quainted with, to enable him to have re course to, in case of need. I can conceive many situations a ship may be placed in, which would call it into action, especially in the survey of coasts and rivers in foreign parts, when at any time with the materials she had on board, a ship's cutter might form the central boat of a very respectable treble one, possessing all the advantages already pointed out. Again, if a ship were stranded on a desolate coast without the loss of her materials, she could make all her boats treble ones with sufficient capacities to convey the whole of her crew with a certain quantity of provisions and water, to any other place of safety. I cannot conclude without remarking, what a pity it is that a book containing nothing but naval inventions and plans relating to nautical matters, has not been published for the exclusive use of seamen, as many plans, particularly "makeshift" ones, which have answered admirably, and others which have been proposed are buried in oblivion, leaving the officer in the time of difficulty to the resources of his own mind, unassisted by the labours and experience of the many. In the hope that I have sufficiently explained the plan, and that the above hint may be taken by some one of your intelligent readers who may have the means of compiling a work of the kind, I remain, Mr. Editor, Your faithful servant, June 12, 1935. THE PLAN FOR PROPELLING STEAMVESSELS BY THE RETROACTIVE FORCE OF A COLUMN OF AIR." (P. 264.) Sir,-After a careful perusal of the article, entitled, "Plan for Propelling Steam-Vessels by the retroactive Force of a Columu of Air," and taking for an exemplification a paddle-board whose superficial area is 12 feet, we come to these conclusions:-1st. That to have an equal surface in the "air" apparatus, the discharge-pipe must be 4 feet in diameter, orth that of the air-cylinder. 2nd. That the air must not only be compressed 10 4th of its original volume, but to th of the same. 3rd. That as the paddleboard must go at the rate of 1,000 feet per minute (or five times that of the piston), therefore the air must go at such a proportionate velocity, so as to produce an effective power equal to a given surface, leverage, and the moving power of a paddle-wheel-board. And, 4th. That the air which has to strike against a given surface of water, must go at the rate of 200 times the velocity of the water itself, i. e. taking into consideration the compressibility of the two fluids. -- There are many other objections against this principle of the "air" striking a body of water. For instance:should the water be low, the air will bubble through, and would have no effect upon the water to drive the vessel either way; nor would such a plan answer at sea; for if the discharge-pipe, or trunk, were fixed parallel to any part of the vessel, as soon as a gale of wind comes on, and the vessel begins to rise and fall, the aperture of the pipe would meet the wind instead of the water. I am, Sir, Your obedient servant, MOHAMMED AL MOONGHEE. Woolwich, July 6th, 1835. ON RAILWAYS. BY JOHN HERAPATH, ESQ. NO. VII. Sir John Rennie's Railway to Brighton and Shoreham. Sir, I regret that incessant engagements should again interrupt the observations I intend to continue on railways. However, I have determined that nothing should prevent my noticing the very droll article in your last, No. 623, on the southern lines, by a Mr. James Combe, "Civil Engineer," especially as I have been fortunate enough, I think, to trace out its origin. Truly, Mr. Editor, the public are much indebied to you for the skill with which you intersperse the amusing with the instructive, the ludicrous with the serious. It is this good tact, I suppose, which makes your Journal so much read, and gives it such extensive circulation. tion elicited the same answer from a second, third, &c. At length, a gentleman informed me that he believed he was one from Sir John Rennie's office, and a pupil of the worthy Knight. Of course, all mystery at once vanished, and I immediately conjectured, but do not like to be positive, that he might be one of those gentlemen who come, like herrings, in shoals from the North, pay 3, 4, or 500l. premium, read the daily papers, smoke their cigars, look at an old theodolite, get a few technical terms, lay aside their tartan petticoats, cover themselves decently with breeches, and, after three or four months, step forth into the world complete at all points from that most perfect of laboratories, Rennie's, for the manufacturing of civil engineers. also followed, that Mr. Combe being Sir John's pupil, and in his office, the letter signed James Combe was written with the privity and knowledge of the said Sir John, if not by the Knight himself. It is with him, consequently, that I consider I have now to do. It This gentleman begins with telling us, that he is 66 personally acquainted (which is more than Mr. Herapath pretends to be) with the engineering details of the subject." Now what, in the name of common sense, have the "engineering de tails" to do with computations of the working merits of the rival lines, which are the subjects of my letter? Certainly, Sir John's good sense must have been lost in one of his dark tunnels, or he would not in such a case talk of " engineering details." However, we shall shortly find that, whatever may be his knowledge of engineering details," his ideas of the true principles of a railway are singularly unique. "In judging of the skill," says the writer, with which this line has been laid down, it must always be remembered, that every other consideration was made subordinate to that of distance.' Here is a confession! The old-fashioned notions of humouring the country in railway designs, on the principle, that railway distances are not to be counted in miles, but in hours and minutes, that the line in which the time of transit, cæteris paribus, is the shortest, is the least expensive to be worked and the most profitable in its returns, are, then, all nonsense, and the rest of the world, the advocates of these notions, blockheads. The only |