The Institute of British Architects is receiving contributions and communications of great importance from scientific men both at home and abroad. An essay is advertised for upon the inte resting subject of concrete, one of the most useful revivals of a mode of c nstruction used by our fore. fathers that we have had to notice of late years. The architects of onr Gothic edifices made most extensive use of concrete in many of their edifices, which remvin even at this period as solid as ever. We cannot but anticipate the most favourable results from the exertions and labours of this useful scientific body, and call upon our practical men connected with building of every grade to answer the call which has been made upon their experience by the offer of a premium upon this important point in construction; for if the Institute receive an essay of adequate inerit, it will doubtless be printed under their sanction, and be highly useful to all engaged in building operations. The Railroad System.-There are no less than 23 published plans of railroads now on the tapis, including those at present in progress. The total amount of capital proposed to be invested is twenty-one millions, an if completed, they would extend over 1,200 miles. Communications received from Mr. Raikes Lieut. Wall-Mr. Lunt-Viator - Mr. MundyMechanicus Minimus-Mr. Matthews. LIST OF NEW PATENTS, GRANTED BE. TWEEN THE 22D OF SEPTEMBER, AND 23D OF OCTOBER, 1835. Joel Spiller, of Battersea, engineer, for an improvement or improvements upon boilers for gene. rating steam, or heating water or other fluids, for useful purposes. September 24; six months to specify. William Samuel Henson, of Chard, Somerset, machinist, for certain improvements in certain ma chinery used for making bobbin-net lace, for the purpose, by which improvements, of making certain kinds of ornamented net or lace with such machinery. October 1; six months. Edwin Hoare, of Stonehouse, Gloucester, ctothier, for a method of preventing the darkness of colour which frequently occurs near the lists as compared with the colour of the middle of woollen cloths, in the process of heating them in water or by steam on rollers. October 1; six months. James Bullough, of B'ackburn, Lancaster, me. chanie, for ce tain improvements in hand-looms and power-looms. October 1; six months. Charles Pierre Devaux, of Fenchurch-street, London, merchant, for certain improvements in smelting iron, stone, or iron ore; being a communication from a foreigner residing abroad. October 8; six months. Apelles Howard, of Stockport, Chester, cottonspinner, and John Scattergood, of Manchester, machine-broker, for their invention of improvements in looms for weaving, whether worked by hand or other power. October 8; six months. Thomas Jevons, of Liverpool, merchant, for certain improved machinery to be used in manufac turing bar or wrought iron into shoes for horses, and also into shapes for other purposes; being a communication from a foreigner residing abroad. October 8; six months. Robert Jupe, of New Bond-street, Hanoversquare, upholsterer, for improvements in ornamental dessert, flower, and other stands. October 9; six months. John William Fraser, of Ludgate-hill, London, artist, for improvements in raising weights or substances from below to the surface of the water. October 15; six months. John Bird, of Birmingham, gentleman, for an improved method of making and compounding printers' ink, paints, and other pigments. October 15; six months. Samuel Draper, of Basford, Nottingham, for improvements in producing plain or ornamental weaving. October 15; six months. David Mushet, of Coleford, Gloucester, ironmaster, for a certain improvement in the art of making or manufacturing bar iron or malleable iron. October 22; six months. Samuel Colt, of Ludgate hill, London, gentleman, for certain improvements applicable to fire-arms. October 22; six months.. Richard Barber, of Leicester, cotton-winder, for an improvement in reels för reeling. October 22; six months. Samuel Slocum, of New-road, St. Pancras, engineer, for improvements in machinery for making pins. October 22; six months. John Dyer, of Mark-lane, London, merchant, for improvements in the materials used for fining or clarifying liquids; being a communication from a foreigner residing abroad. October 22; six months William Patterson, of Dublin, gentleman, for an improvement in converting hides and skins into leather by the application of matter obtained from a material not hitherto used for that purpose. October 22; six months. George Baxter, of Charterhouse-square, engraver, for improvements in producing coloured steel-plate, copper-plate, and other impressions. October 23; six months. James Walton, of Sowerby-bridge, Halifax, York, frizer, for certain improvements for dressing, finishing, and setting the face on woollen or other cloths requiring such process. October 23; six months. John Baring, of Bishopsgate-street, London, Esq, for an invention of a machine for combing r brushing wo 1, flax, and other fibrous materials, into teeth set in a cylinder, or otherwise, for the purpose of separating the longer from the shorter fibre; being a communication from a foreigner residing abroad. October 23; six months. The Supplement to the last volume, containing title, index, &c. and portrait of Charles Vignoles, Esq., C. E., is just published, price 6d. Also, the volume complete, in boards, price 9s. 6d. Errata in Mr. Steer's Opinion, 3d paragraph, line 4, dele "an." In next page (63), line 3, for "came" read "come;" and line 15, for "on" read ain." Patents taken out with economy and de spatch; Specifications prepared or revised; Ca. veats entered; and generally every Branch of Patent Business promptly transacted. Drawings of Machinery also executed by skilful assistants, on the shortest notice. 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. BENNI, 55, Rue Neuve, Saint Augustin, Paris. CUNNINGHAM and SALMON, Printers, Fleet-street. ON RAILWAY PLATFORMS. BY JOSEPH JOPLING, ESQ., ARCHITECT. Sir,-Supposing the weight of the stone blocks, at the distance they are apart near Chalk Farm, to be sufficient for steadying the rails for such loads, and at such velocities as it is intended should pass along that railway, I have been considering whether it is possible to distribute the same weight in any other way more advantageously, and what description of material is best calculated for that purpose. I have formed several plans, but venture first to submt to the consideration of engineers a slate-platform, with rails screwed directly thereto, that is, without chairs. I take it for granted that the less the distance is between the top of a rail and the foundation or bed on which the stone is laid to which it is to be affixed, the better, so that the rail be of sufficient strength and the stone be of sufficient thickness to hold firmly the fastenings for the rail. Also, that the nearer the points for supporting a rail are to each other, the less the vibration will be. Again, that if any rail be supported throughout its length, the vertical vibration of it will be the least possible. And further, that the nearer the points for fixing a rail to its stone support are to each other, the less strain there will be upon each. The difference between the method adopted for the London and Birmingham Railway and the one now submitted to your readers, will appear obvious by the accompanying figures and the following description. Fig. 1 is an isometrical representation of the stone blocks as they are placed for the chairs to support the rails, near Chalk Farm. The distance between the centres of the blocks under each rail is 5 feet; and the distance from the centre of one block to the centre of the next under the same rail is 3 feet. The top and bed of each block is 2 feet square, and the depth 12 inches. Therefore, each block contains 4 cubical feet, and each has a bed of 4 superficial feet; and, consequently, there are 8 cubical feet of stone, having in every yard in the direction of the length of each railway 8 superficial feet of bed. A chair is fixed over the centre of each block, and the distance from the top of the rail to the bottom or bed of the block is 18 inches. This will appear more evident by the transverse section, fig. 4, showing two of the blocks, and the position of the tops of the rails. The dotted lines abc, from the top of each rail to the angle of each block on its bed, shows the greatest angle of resistance they have to lateral vibration. If the blocks were not placed diagonally, the angle of resistance would be much less, but probably more correct. It is, indeed, considered to be doubtful whether any advantage is obtained by the diagonal position of the blocks. Fig. 2 represents a platform of slate, nearly 5 inches thick, and 6 feet 6 inches wide, containing the same cubical quantity per yard as the stone blocks at Chalk Farm. Fig. 3 is a transverse section of the same, showing the top of each rail. The dotted lines abc show the angle which the top of each rail makes with the lateral extremities of the bed of the slate platform. The angles abc, in fig. 3, are much greater than the angles abc, fig. 4; besides, the latter is considerably too much. Therefore, the platform, it is considered, would hold the rails much steadier than the blocks at Chalk Farm; the weight per yard of each being the same, and both being bedded in the same way; Fig. 5 is the section of a rail proposed to be affixed directly to the slate platform, by means of bolts and copper or brass nuts introduced into the slate. If there are eight of these bolts in each yard, the points of fastening to the platform would be four times as many as those to the stone blocks, and the strain upon each, therefore, if the rail was not bedded, would only be th; but as the rail is proposed to be bedded throughout on felt, and a leather collar under the head of each bolt, any jar or vibration the rail might have, it is considered, would scarcely be perceptible. The inner side of the rail, and the face of the slate under it, to be made quite fair. At each end of each piece of rail is to be a mortice, the vertical section of which is shown by the lines abcd on this figure. Fig. 6 shows the plan of this rail where two lengths meet, with the mortice in each, and the wedge which keeps them fair, which, as well as the elliptical holes for the bolts, allows for expansion and contraction. Two bolt-heads are also shown. This possibly may be sufficient for the Your obedient servant, 34, Somerset-street, Oct. 15, 1835. ON THE PROBABLE CONNEXION BETWEEN ELECTRICITY AND VEGETATION. Sir, -The very handsome mention which is made of a manuscript of mine upon the subject of the connexion between electricity and vegetation, by Mr. Weekes, in the last volume of your periodical, p. 394, and the great obligations I am under to that gentleman for his very able and generous co-operation in pursuing the inquiry, encourage me in offering some particulars of our joint observations to the notice of your readers. In that manuscript I have endeavoured to bring together lights from various sources of information bearing upon the general subject, and combining to show the agency of electricity through the several stages of vegetation. I am sensible, however, that this very extensive subject requires much further investigation, while the mention of such facts as have fallen under my notice and that of Mr. W., in his kind exertions to forward my views, may be of use in drawing forth the remarks of some of your other correspondents. Having learnt from the statements of the late Mr. Cavallo, and the more re cent observations of Mr. Sturgeon, that our atmosphere is in a constant state of positive electricity with respect to the earth, and reflecting on its suitability to exert a continual action upon bodies so organized as those of plants, I was led to try the conducting agency of the pointed extremities of leaves; when it immediately appeared from every mode of trial that they are the most potent of conductors, not excepting the most acute metallic points. My proofs consisted simply in presenting them to the prime conductor of an electrical machine, or in passing the contents of a charged jar through them, when it appeared that the light entering or issuing from them was much more brilliant; that it would be seen upon the vegetable point to the exclusion of any light upon the metallic point when held equidistant, and that the former would continue to be illuminated at a much greater distance from the prime-conductor than the latter. The effects produced upon the electrometer affixed to the primeconductor by the vegetable point, also much exceeded those produced by that of metal. When the human body was made a part of the circuit in discharging a jar through a vegetable point, the shock was barely perceptible, although the discharge was so complete as to leave hardly any residuum, whereas, a similar charge passed through a metallic point caused a very sensible shock. Mr. Weekes on being made acquainted with several of the above facts, very obligingly entered on a course of experiments in illustration of the principle, by which he has shown with scientific exactness the superiority of vegetable points to those of metal, both in artificial electricity and in their application to the electricity of the atmosphere. As he has generously consigned to me the task of making known his experiments, I have great pleasure in doing so through the medium of your valuable Magazine, in his own words. After some apology for a previous delay, he writes me as follows:-"However, I find I have by no means had too much time for a fair and impartial examination of the subject, the interest of which to me has been such as to excite experiment far beyond my intentions at the outset. The final result in my mind is an entire conviction that your opinions are well founded, and have stood the test of the severest trials to which they could be subjected. The vast superiority of vegetable over metallic points in the drawing off and accumulating electric matter, is, I conceive, a subject of great interest and importance. A coated jar having 46 inches of metallic surface, was repeatedly discharged by the activity of a vegetable point in 4 min. 6 sec., while the same jar charged to the same degree required 11 min. 18 sec. to free it from its electric contents by means of a metallic point-the points in both cases being equidistant. I find, also, that Bennet's gold-leaf electroscope is powerfully affected by a charged jar at the distance of nearly 7 feet, when the brass cap of the instrument is furnished with a branch of the shrub called Butcher's Broom, and which I have found of great use in my experiments. The same delicate instrument, when mounted with pointed metallic wires, is not perceptibly affected until the charged jar approaches to within 2 feet of the cap." In order to try the electric action of vegetable points immediately upon the atinosphere, Mr. Weekes placed "a large street-lamp in an inverted position, mounted with a brass cap, through which passed a stout wire with a brass knob" at its nether extremity," and a pair of small pith balls attached" by threads "to the wire above the knob." Within the glass was placed "a portable stand with two metallic discs, one on each side of the wire, and rising to a level with the pith balls " To the summit of the wire he attached " a small branch of the butcher's broom." "This apparatus," he proceeds, I have many weeks past had in almost daily use, nor can I express the pleasure it has afforded to myself and friends by its frequent indications of atmospheric electricity; for armed with vegetable detectors, it has shown symptoms of electricity by the passing of clouds at a great altitude, and under various other circumstances, in which electrometers with metallic points placed by its side gave no indication whatever. This appears to me so decided a proof of the superiority of vegetable conductors, that it admits of no contradiction." The letter in which these accurate and decisive experiments are related, is dated the Sth of May 1828; and as they were recently made, they admirably illustrate the electrical state of plants and their action on the atmosphere in the spring season. This is no doubt the season of their greatest electric as well as vegetative activity, agreeably to which, in my first experiments made in the month of June, a blade of grass and a metallic point being mutually presented to the prime-conductor, the first continued to be illuminated till it had reached at least four times the distance, at which the latter ceased to exhibit any light, that is, at the distance of about 14 feet from the electrified body; whereas, in a similar experiment made in October, the grass-point affected the ball of the electrometer appended to the prime-conductor at a distance only of 19 inches, when a pointed metal of corresponding length, i. e 5 inches, would affect it in an equal degree at the distance of 9 inches. It cannot but be evident that very im. portant consequences must flow from such extraordinary conducting energies in plants, more particularly as manifested through the acute extremities of |