1840.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



.307 



the subject ; anj after all, sliould probably fail to Rive a clear idea of the 

 construction without the aid of the drawing ; we, therefore, skip over to the 

 conchidinf;' paragraph. 



"1 have represented tlie valve as fixed in a locli-gate, but I by no means 

 intend to restrict myself in my said improvement to valves placed in this par- 

 ticular situation ; neither do I claim as my invent on llie manner of applying 

 the lever and screw as exhibited in the drawing. What I do claim as my 

 invention, and desire to secure by letters patent, is the application of the 

 hydrostatic pressure, to open sliding valves for canal and river locks, and 

 making such improvements in the construction of the said valves, and in the 

 form of the apertures to which they are applieil, as will adipt them to the 

 application of this pressure, as herein descnl)ed." — Franklin Journal. 



RAILWAY CAUTION. 



Sir — Being a frequent traveller on railways, and generally choosing the 

 slow trains, I beg leave to trespass on your valuable columns by suggesting 

 an expedient by which, in my humble opinion, travellers situated like myself 

 may avoid the disagreeable necessity of being run over by quicker trains. 

 The plan to which I allude is this : — that at each station on the line of rail- 

 way be placed a large dial, similar to a clock face, with minutes marked upon 

 it from 1 to 60. It should liave one moveable hand of sufficient size to be 

 distinctly visible to the guard and engineer as they tiy past ; the officer in 

 attendance to fix the hand at that pai'ticular number on the dial that may 

 denote the number of minutes which have elapsed since the preceding train 

 passed. This signal might be illuminated at night. Or a perfect clock face 

 might be adopteil to denote the hours in addition to the minutes. 



I am, Sir, 

 Kenninqfon, Your obedient servant, 



Oct.2Wi, 1840. T. W. 



ROTARY ENGINE. 



An engine, upon tliis principle, was latelytried in Leeds, in the pre- 

 sence of several engineers. Its enormous power, in so small a compass, 

 (the whole machinery, with the exception of the fly-wheel, being contained 

 in a box 2 J inches in depth and 10 inches diameter) surprised every one pre- 

 sent ; the speed was tremendous, making from 600 to 700 revolutions per 

 minute. Its power was tested by placing breaks upon the fly-wheel, which 

 was done to the extent that the shaft was actually twisted in two pieces, but 

 no accident occurred. It is the intention of the inventor to apply the ma- 

 chine to propel carriages on common roads, for which purpose it appears ad- 

 mirably adapted ; likewise for the purposes of marine navigation, where tlie 

 small quantity of room it requires is a material consideration ; in short, it 

 will answer all the purposes wherein steam is required ; and the expense will 

 be considerably abridged. The inventor is Josh. Briggs, watchmaker, of this 

 town. — Jieeds Intelligencer. 



STEAM NAVIGATION. 



INCRUSTATION STEAM ENGINE BOILERS. 



We are informed by L'Echo dii ilonde Savant, of the 25th of July, that M. 

 Edouard Richard had presented to the Geological Society of France a calca- 

 reous incrustation, which must be considered of great value, as it was not 

 formed in the boiler, but in the cylinder of the engine, and beneath the pis- 

 ton. The incrustation formed a disc 12 J centimetres in thickness; and in 

 consequence of tlic pressure of the piston, it is so hard that it is capable of 

 receiving as high a polish as the densest marble. It is evident, therefore, 

 that explosions may be produced as well by calcareous concretions of the cy- 

 linders as of the boilers of steam engines. The engine from which this spe- 

 cimen was procured, has been used for the purpose of pumping water from 

 the mine of Auzin. and has been built after Newcomen's plan. — In L'Echo du 

 Monde Savant of August the 5th, we find a communication upon the subject 

 of steam-ljoiler explosions by M. Flesselle, a retired officer of the French 

 Marine, resident at Graville, near Havre. M. Flesselle suggests, that, in order 

 to prevent the formation of calcareous incrustations, (which have long been 

 considered tlie principal causes of accident,) some common salt or muriate of 

 potash, sliould be \mi into the boiler with each fresh supply of water. M. 

 Flesselle recommends this measure, because the incrustations are formed of 

 the carbonate, the sulphate, and perhaps the phosphate of lime — (salts, in- 

 soluble, or sparingly soluble) ; and these salts, boiled with the muriate of 

 soda (common salt), or muriate of potash, will undergo double decomposition 

 with these muriates; the products being the carbonate, sulphate, and phos- 

 phate of soda, and the muriate of lime — salts all of which are soluble. 



M. Flesselle says that M. Chaix, of Maurice, has invented a method of pre- 



venting explosions, which appears to have been adopted with success in the 

 French government steam vessels ; but M. F. considers that auxiliary means 

 also are requisite — ^and we tliink he is right ; for the fact we have related re- 

 garding the engine at Auzin, proves that we should avail ourselves of every 

 cheap and simple aid to prevent the fearful accidents to which incrustations 

 may give rise, seeing that the snipliate, carbonate, and phosphate of lime 

 may be held in suspension by the steam — be carried by it in a state of minute 

 molecular division even into the cylinders — and there also be deposited in the 

 form of hard concretions. — The method of M. Flesselle, seeming founded on 

 correct chemical principles, will, we hope, be put to the test of experience, 

 by some of the numerous engineers of our neighbourhood. We shall feel 

 great pleasure in recording the residt. 



In England the precaution taken against incrustations is an index of the 

 density of the fluid in the boiler ; but this is evidently inadequate — for the 

 calcareous particles are conveyed by the steam into the pipes and cylinder. 

 Perhaps some of our scientific readers will have the goodness to inform us 

 whether the English method of preventing incrustations is identical with that 

 of M. ChaLx. — Gateshead Observer. 



THE PROPELLER STEAM-BOAT. 



This vessel was built in the yard of Mr. Dichburn, at Blackwall- The 

 engine by » hich her paddles, or propellers, as they are termed, are worked, 

 was made by Mr. Beale, the engineer, at his premises at Greenwich. She is 

 a small vessel, but very elegant in her proportions, and formed to cut through 

 ths water with great rapidity. The engine is of 24 horse power. The pro- 

 pellers differ from the paddle-wheels used by other steamers, in being single 

 bladi'S o! iron, only one b'ade on each side of the vessel, and not a series of 

 blades brought into the water by the revolution of wheels. Kach blade is 

 very broad and large, and dips almost perpendicularly into the water, so that 

 the concussion fomied by the blades of paddle-wheels dipping into the water 

 at angles is avoided, and the consequent unpleasant vibration of the vessel. 

 Directly the liladc rlips into the water it is forced back by an arm or limli of 

 iron, performing a motion similar to the leg and web-foot of an aquatic bird, 

 and by means of this motion the vessel is propelled forward. She can per- 

 form fnim 10 to 11 knots or miles an hour. The appearanceof the propellers 

 is like that of the legs of a grasshopper, and when in motion fheir action in 

 some degree resembles the legs of that insect in its walk. One great ad- 

 vantage is, that the propellers occasion no swell in the wafer, no wake or 

 trough in the river, and no backwater, so that no danger is occasioned to 

 small boats by the rapidity of her progress. This vessel now runs hourly 

 between Blackwall and Greenwich, and appears to be a great favourite, from 

 the number of passengers she is continually conveying backwards and for- 

 wards between tliose places. — Times. 



Iron Steamers. — Anotlier iron steam vessel was launched from the yard of 

 Messrs. William Fairbairn and Co , at Millwall, on Tuesday the 27th ult., 

 being the second of three vessels for New South Wales, intended for the trade 

 from Sydney to the Hunter's River. She glided gracefully into the water 

 amid the cheers of a number of spectators, and of nearly 600 men who are 

 employed on the premises, and was named The Thistle. She is 145 feet long, 

 20 feet 6 inches beam, and 11 feet 6 inches depth of hold, about 305 tons 

 burthen, and drew when launched only 3 feet 6 inches of water upon an even 

 keel. — The Rose, the first of the trio, has sailed for her destination, and she 

 proved herself before leaving the river to have a speed of 13. 5 miles per hour, 

 and to be one of the strongest and best sea going vessels afloat. The frames 

 of these vessels were much admired on account of their great strength, as 

 well as the manner in which the whole was put together. The engines, 

 which are of 50 horsepower each, were also manufactured, and the whole of 

 the fittings executed by Messrs. Fairbairn and Co., within the same premises. 

 The extent of work which was in progress in the yard, and in the engine 

 manufactory, &c., seemed to surprize many of the gentlemen present, wha 

 remembered the place in which these operations are now carried on as a piece 

 of marsh land overflowed by the tide little more than four years ago. Withia 

 this period the whole of the extensive workshops and iron foundry have been 

 built. Thirty-one iron vessels, to the amount of 6100 tons have been con- 

 structed, and steam engines to the extent of 1260 horse power have been 

 manufactured.^An iron schooner intended for the coasting trade from Lon- 

 don, and various steam boats, are now in course of preparation, so that it 

 seems this material is making rapid strides in the public estimation for the 

 purposes of ship building. 



Tf'ar Steamer.— It will be recollected that the steamer of war Polyphemus, 

 of 800 tons burthen, was launched at Chatham, on Monday the 28th of 

 September, the same day that the London of 92 guns was launched, the 

 former vessel proceeded up on the following Thursday, the 1st of October, to 

 the engineering establishment of the Messrs. Seawards and Capel, of London, 

 and they have comjiletely equipped this fine vessel with engines of 200 horses 

 power, with all her fittings, s]iare gear, implements and stores, and coal boxes 

 of wrought iron to contain 220 tons of coals, in the short space of 22 work- 

 ing days ; being the shortest time upon record that a vessel of this magnitude 

 has been fitted. She proceeded down by steam to Chatham on ^^'ednesday 

 the 28th instant, to take in lier masts, being quite completed in her machinery ; 

 it is considered that it would require a period of six months in any port of 



