1842 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



this fact, it is still so; by loss on the slide valve you save steam, but 

 yon reduce your power* in the same proportion ; and was moderate 

 consumption of fuel the only desideratum it is easily obtained ; vou 

 may save coal by not using sUam, and that is simplv done by prevent- 

 ing its ingress to the cylinder. Thus actual power is reduced, but 

 nominal pow er is fixed, and hence the result of 6i lb. consumed on 

 board the Gorgon. 



I may here incidentally obsers-e that a good marine engine should 

 exert an average pressure on the piston of 141b. per square inch, and 

 this exclusive of all friction of the moving parts; this, according to 

 Mr. Watt's computation is just double the nominal power. If under 

 these circu mstances it consumes 9 lb. of coal per nominal horse power per 

 hour, or 4i actual horse power, you may be content. I have known this 

 exceeded, but think it rare ; a pressure of 10 to IGi lb. on the inch is 

 common in these days, and that with a boiler pressure of U lb. There- 

 fore to form a fair experiment of the consumption we ought to be 

 favoured with an iiHlicutor figure, showing the average pressure, with 

 the speed of the piston per minute. 



The Gorgon's cylinders are 66 inches diameter and 5 ft.G in. stroke, 

 and according to Mr. Watt's computation, (I take his data as I con- 

 sider it beyond cavil), should make 2U strokes per minute, or 220 feet, 

 producing a power of 160 horses, or 320 for both engines. This is 

 just equal to 18-57 cwt. per hour, is this fact » I put it Sir, to your 

 own knowledge, as well as to that of your general readers. 



One other point only remains to be considered, the actual speed of 

 these Gorgon s engines. I am told in consequence of the great im- 

 mersion of the Gorgon, her engines seldom make more than U to 15 

 strokes per minute, if this is true the mystery is solved, the consump- 

 tion of coal is increased at once in the proportion of 20 to 14, equal 

 9i lb. per nominal horse, about the usual thing supposing the actual 

 power double as above stated. 



Of the " Styx" I can speak with confidence, on her trial in the river, 

 with my Lords and a large party on board, with coal enough for the 

 trip, no masts, stores ("except, to the credit of the engineers be it said, 

 no mean supply of the rery good things of this world), guns, &c., at 

 her light draft she made 17 strokes per minute, and when loaded it is 

 reasonable to suppose the increased resistance would reduce that two 

 or even three strokes per minute at least ; therefore how utterly in- 

 conclusive it would be to form any judgment as to the consumption of 

 coal upon such data. No, this may do for the government folks, but 

 the steam public will require deeper investigation ; let us have an in- 

 dicator figure, the number of strokes per minute, the speed of vessel 

 with her immersed section, and then we shall be enabled to see if 

 modern ingenuity has done more than old "Gutzmer" did in the 

 "Tourist." 



There are other defects attached to the Gorgon engine which de- 

 serve notice. It has been frequently observed, even bv unscientific 

 persons, that in the " beam engines" every part was beautifully adopted 

 to iU purjpose, and was so well balanced, that disconnected from the 

 shaft it preserved its position, it results that its motion is equable and 

 smooth, with a minimum friction on the moving parts. Although I 

 differ from those who suppose there is a mechantcat loss of power in 

 the use of the short connecting rod, still I conceive the most sanguine 

 supporter of the "direct engine" must allow there i» a loss of power 

 from attendant causes, the undue friction thrown upon the parallel 

 motion upon the shaft bearings and other parU, in consequence of the 

 oblique action of the connecting rod, and more than all the irregiUar 

 motion ariMng from the weight of the pistons, connecting rods, cranks, 

 cross bars, &c. being totally unbalanced, except bv the paddle wheel 

 which I consider so rude as out of the pale of civ'ilization, and which' 

 by tlie bye, cannot be carried into etfect when any app.-irafus is fixed 

 for disengaging the shaf^ as the paddle wheel woul.l not revolve, the 

 very end to be obtained by such device. 



The ttrlttr of ihu piipcr <lon not il.ink it necessary to explain ihc theory 

 ofexp:insion, lo show llmt ihc power lost Ly it is ,,»/ in proiH-riion to tl.,. 

 •team 5^vo<l. nor is it worth while to .how that Ihe »|we.l ol the ship «.,., 1,1 

 !>« reduced m the cul>e rouu ol the lost power, his desire is to prove Ihc i,n- 

 soundmsi of reasoning up n nominal liursc power consumption. 



Another disadvantage is that in order to get a moderately long con- 

 necting rod, you are obliged to construct your paddle whee'l much too 

 large in diameter for the stroke of the engine, and in order to reduce 

 your resistance, to contract the length of the board ; this applies to all 

 our Government vessels hitherto fitted with direct engines, and in fact 

 to this I principally ascribe their low speeds. 



Puffing is a horrid resource ; I have been amused to see the manner 

 in which the Gorgon and Cyclops were brought l>efore the public on 

 the recent bombardment of the Syrian coast; surely this is unfair and not 

 national. The Phenix, Medea, Hecla, Hydra and many other? did their 

 duly, which I presume is all the first named were called upon to per- 

 form. 



One observation more, and I fear I am only disseminating a generally 

 known fact, that the great majority of our war steamers have rtry Ion 

 relociUes. I know not what oilier countries possess, but this must be 

 evident to all, that (putting aside great disparity of force), the fastest 

 steamer will be the conqueror, and thus as In the American war, our 

 noble tars will be sacrificed to the miserable inefficiency of those who 

 have the governance of such matters. 



I conclude with a prophecy. Fashion must have its course in steam 

 as in other matters, but ere long we shall come back to the scandalized 

 " Beam engine." The Gorgons may shake their heads, and Cyclops 

 wink their "central orbs," they will meet the fate of the " To'uritt," 

 now propelled by a pair of beam engines. Like in the paddle wheel 

 mania, we gyrated from poor Buchanan who "shone" in lsl4, 

 through a vast series of minor inventors down to Morgan, who iffent 

 put in 1S3S or thereabouts;— this is all very well, and is good for trade, 

 but who pays ? 



I remain, Sir, your's truly, 



Vl-lcax. 

 London, December 9, ISll. 



ON THE USE OF GOLD IN DECORATION. 

 Since architects are beginning to pay more attention than formerly 

 to the minor parts of decoration, it may not be venturing out of their 

 province to turn their attention to a very important branch of it— 

 though it is ground on which, from being confined by the impregnable 

 laws of fashiun, it is more dangerous to tread than even the slippery 

 path selected by Mr. Bartliolomew. When we have designed our de- 

 coration with the greatest attention to harmonious colouring, taking 

 care that each may have its proper proportions, and making a cautious 

 use of bright colours out of regard to those which are more subdued— 

 the artist comes, and to the injury of his own works, as wed as those 

 of the architect, covers the wall with a phalanx of rich gold frames of 

 precisely the same character, whatever may be the tone of the room or 

 the nature of the picture. If the statements of Mr. Clarke be correct, 

 that yellow is to be useil with great caution ami never in large quan- 

 tities, and it un<loubtedly is correct, and is universally allowed to be 

 so, except in this one point, it surely is contrary to every principle of 

 colouring, either in decoration or the management of a picture, to in- 

 troduce this dangerous material in a manner entirely regardless of 

 surrounding or surrounded objects. Pictures of the niost deliciie as 

 well as the boldest character have frames to match each other rather 

 than themselves — and this because no one has the courage to propose 

 a remedy. Artists are not much afraid to intimate with caution that 

 the talon-like form in wiiich the finger nails arc sulTt-red to luxuriate, 

 has no authority in the antique. Some one more h.ardy than tli,' rest 

 suggests to a la<ly that if her daughter's waist was really pinched as 

 small as she wished it to be represenlevi, "she would not be alive a 

 minute." But the other practice is too finely paid, for any one to 

 attempt its removal — though wc must not despair of time etreoting 

 what no other less potent .igent can. Equally absurd ami deeply rooted 

 fashions have given w.iy. It has been discovered that the human form 

 is seen to more advant.ig,- in a simple garb, than when the upper ex- 

 tremity appears emerging from a gigantic cheese. And posMbly it 

 may be found that works of art, more precious than diamonds, like 



