1843.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL 



397 



economical purposes. By Mr. Southern's rules (an authority above 

 question) as given by Farey, page 73, it follows that the vapour arising 

 from water heated to 102° is equal to a pressure of 1-97 in. of mercury, 

 therefore taking 27*54- 1-97 we have 29-47 in., or only 0*53 in. below 

 the mean barometric column in this country, which we opine, leaves 

 a very small margin for inventors. We now pass to the stcond 

 branch, which describes a double cylinder engine. Woolf again, with 

 a small spice of Mr. Joseph Maudslay's patent of 1S41 (before adverted 

 to) we have here, two piston rods and an annular cylinder, the internal 

 cylinder to be used a la Woolf, for high steam ; besides a patent by 

 Mr. Gillman has been already secured for using two cylinders one 

 within the other, and adopted for the same purposes as Mr. Parsons 

 proposes. 



Without being hypercritical upon descriptive drawings to so small 

 a scale, we shall content ourselves with remarking, that we cannot see 

 how Mr. Parsons means to fit, adjust, and repair the. small sliding 

 valve, E F, Fig. 7, sheet A ; or how to make good the wear and tear 

 of the valves, N and M, with their Iriple faces, or to secure and make 

 tight the cylinder cover; and lastly, how all this complication is to be 

 manipulated and worked ? These are practical points which suggest 

 themselves to us, for the means described in p. 6 are, in our opinion, 

 totally inefficacious. 



The third branch comprises a scheme that really provokes our 

 cachinnation ; — we believe it to be entirely new, although Mr. Parsons 

 does not claim its leading principle — the reciprocation of the cylinder 

 upon a fixed piston, stating it to have been used : if so, we conceive it 

 must have been on a very small scale. 



The fourth branch consists of an arrangement of steam engine, "hav- 

 ing for its object the better application of the power for driving screw 

 propellers." It is on Woolf's plan, but evinces considerable inge- 

 nuity ; — but it is objectionable on account of the spur gearing, which 

 has been found the great difficulty in applying and working screw 

 propellers. 



The fifth branch, for disconnecting paddle-wheels from the engines, 

 so that they may revolve when the ship is under sail, would be ex- 

 pensive in fitting, and useless in practice. Many other schemes are 

 known of far greater superiority; among others, that of Tiewhit is 

 prominent. 



The sixth and seventh branches introduce more complication where 

 there is necessarily too much already, namely, in the locomotive engine. 

 The eighth branch is an invention for supporting the main plummer 

 blocks of marine engines. This is verily an "invention," for we feel 

 assured nothing of the kind was ever seen before. This, like the 

 third branch, assures us of what we previously had an idea — that 

 Mr. Parsons's ingenuity far exceeds his practical knowledge. 



The ninth branch, an improved packing for pistons and shifting 

 boxes, like the fifth, is useless, because far better means are in use, as 

 those of Maudslay and of Robert Napier. 



The tenth branch, an improved cock aud plug, is absurd. 

 The eleventh branch, for preventing cams turning round with the 

 shaft, is absolutely preposterous, because it can be, and is done, by 

 more simple arrangements. 



This, then, completes our analysis of Mr. Parsons' patent. We 

 cannot, however, conclude without protesting against this wholesale 

 mode of making up a patent, and observing that he cannot re- 

 concile, with the honour and dignity of the profession, thus bringing 

 together other men's inventions, disguise them under a thin veil of 

 doubtful improvement, and make the compound the subject for a 

 patent. 



WealCs Quarterly Papers 

 John Weale. 



TVcal, 

 John Weale 



Engineering 

 quarterly Papers on Architecture. 



Part I. London: 



Part I. London : 



Mr. Weale, having succeeded so well with some of his annual 

 publications, particularly the papers of the corps of Royal Engineers, 

 has now commenced two quarterly miscellanies, one devoted to engi- 

 neering, and the other to architecture, as the means of preserving 

 those papers which, without being of sufficient bulk to justify an inde- 

 pendent publication, are yet too long fur our columns, or require a 

 greater extent of illustration than we can devote to any one subject. 

 We see that the design includes scientific memoirs, the lives of emi- 

 nent professional men, republications of American works, and trans- 

 lations of important communications from the French, Dutch, and 

 other foreign languages. When it is considered that the works will 

 each torm a handsome volume at the end of the year, expensively 

 llustrated, and at a moderate price, we are sure these new enterprises 



will receive that support from the two professions which they well 

 merit. 



The engineering part not inappropriately commences with a 

 copious life of Brindley by Mr. Hughes, C. E. It gives full details as 

 to his works, and is illustrated with a copper-plate portrait. Another 

 memoir succeeds this, namely, one on Wm. Chapman, CIO., for 

 whom is claimed the invention of the skew arch, first applied by him, 

 in 17S7, on the Kildare County Canal in Ireland. Originally employed 

 in the merchant navy, his attention was early directed to hydraulic 

 engineering, which, on the advice of Watt, Bonlton, and others, he 

 determined on pursuing as his profession. He was consequently 

 employed on a number of canals and docks, and, among others, on the 

 London Docks. He was also the author of several useful professional 

 works, ami of many valuable inventions and improvements in mechan- 

 ical processes, particularly in rope-making, and the shipment of coals. 



We have afterwards a paper on the dredging machine, with three 

 engravings, and entering into the history of that invention, but to 

 which, as it is likely to be the subject of controversy in this Journal, 

 we will not at present enter. The plates describe a machine con- 

 structed under the direction of the late Mr. Rennie, in 1S02, for rais- 

 ing mud out of Messrs. Perry's dock at Blackwall, and another used 

 at the Hull docks in 1S0S. In this paper it states that "the piles (600 

 in number) for the coffer-dam of the Wapping entrance of the London 

 Docks, constructed by Mr. Rennie, were driven by one of Boulton & 

 Watt's eight-horse engines in the year 1801. Next comes an account 

 of the engines of the Russian war steam frigate, the Kamschatka, 

 constructed at New York by Messrs. R. & G. L. Schuyler. Four 

 plates illustrate this subject, and a description is given of several 

 peculiarities in the construction, for which we cannot say much in its 

 favour. We will, however, let the engineers give their own reasons. 



" In the United States, the most aproved method of using steam is 

 expansively, that is to say, by having a high pressure in the boiler, 

 cutting off the steam from the cylinder after the piston has performed 

 say one quarter of its stroke, and allowing this high steam to expand 

 through the remaining three quarters of the stroke. To this system 

 to work to the best advantage very long cylinders are required. 



" Having determined upon adhering to this method, so successful 

 in our river steamers, it became necessary to adopt some plan by 

 which the length of cylinder could be preserved without elevating the 

 engines above the deck, or cramping the action of the connecting rod, 

 as is seen in some English government steamers. By reference to the 

 drawing, you will observe that any desired length of stroke can be 

 obtained without adding to the elevation of the engines, and also that 

 the connecting rod has great length and free action. The advantages 

 of placing the cylinders in a horizontal position, firmly secured to the 

 keelsons, and bolted down through the hull, are also very great. The 

 strain of the engine is fore and aft, which tends greatly to relieve the 

 ship. The engine takes up much less space in width than any other; 

 there is consequently room for coal-bunkers four feet wide on eacli 

 side, thereby rendering the engines completely shot proof. In this 

 plan we retain vertical air pumps, force pumps, and valves. The 

 steam and exhaustion valves are of the kind commonly used in the 

 United States, known as double balance valves. The valves used for 

 expansion are of our own contrivance, and peculiar to this ship; they 

 are worked by a separate eccentric and rocker shaft, which is so set 

 as to follow the motion of the steam valve, cutting off the steam at 

 any point of the stroke which may be desired ; they can be thrown out 

 of gear instantaneously, without stopping the engine. The triangle 

 or half beam, which forms the connexion between the piston rod and 

 the connecting rod and cranks of the engine, can be so arranged, by 

 altering the centres, as to make the cranks of any length which is 

 thought most advisable, without reference to the length of stroke of 

 the piston. In the case of the Kamschatka's engine, the cylinders are 

 62£ in diameter, and have ten feet stroke, while the cranks are but 

 four feet in length, and you will readily perceive that any leverage 

 lost in shortening the crank is exactly counterbalanced by the gain 

 upon the half beam. The steam is cut off at one third of the length 

 of the cylinder. The number of strokes of the piston are from 26 to 

 34 per minute — on an average 30; thus requiring 1260 cubic feet of 

 steam per minute, of an average pressure of 12 lbs. per square inch 

 above the atmosphere. She has four copper boilers, (constructed for 

 burning anthracite coal), each 10 feet long, 12 feet 6 iuches wide, and 

 11 feet high ; the flues all centering in one chimney, 7 feet in dia- 

 meter, and 46 feet high above deck. Each boiler has four separate 

 furnaces; the heated current is taken from each furnace through 400 

 copper tubes, each 28 inches long, and one inch in diameter in the 

 clear. From any one of these furnaces, by a peculiar construction of 

 a revolving grate, the coals can be instantly dropped, and the tubes in 

 that furnace can be swept out and cleaned while all the other furnaces 



