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THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Feb. 



The annexed sketch shows the arrange- 

 ment of the drums, straps, &c. The 

 strap A was 4i inches broad, B, on account 

 of its greater velocity, was at first made 

 only 2 inches broad, but when it came to 

 be tried the consequence was, its not being 

 able to drive the machine without being so 

 tight as to be constantly breaking, where- 

 fore it was replaced by one an inch broader; 

 this too was far from performing its work 

 in a satisfactory manner. Although this 

 strap was two-thirds as broad as the driv- 

 ing strap A, and travelled at a velocity 

 three times as great, it was still found ne- 

 cessary to increase its breadth to 4 inches, and even then it required considerably more atten- 

 tion to prevent it from slipping than A. 



The peculiarity of this circumstance induced me to give the matter a little consideration. 

 The proportions of the pulleys were such as caused the velocity of B to be three times as great 

 as that of A; this informed me that a given force applied to C would only produce one-third of 

 its effect atD, and consequently, that the strap A demanded a breadth three times that of B, 

 which I knew not to be the case in practice. A second thought reminded me of having occa- 

 sionally observed the pulley E perfectly still, at the same time the strap B was carried round 

 with the drum D at full velocity. This pointed my attention towards the very small amount of 

 strap-surface acting upon E, compared with that acting upon C. At this moment it occurred 

 to my mind, that the breadth for the strap B, necessary to communicate power to E proportional 

 to that possessed by C, depended not upon the breadth of the strap A, but upon the amount 

 of its surface acting upon the circumference ofC 



I next proceeded to ascertain the length of strap aC a, which being multiplied by 44 inches 

 (its breadth), gave 12 1-5 inches, the amount of its surface in contact with the pulley. Then 

 as 1 (the velocity of A) : 121'5 : : 3 (the velocity of B) : 40-5 the amount of surface required to act upon E. Now 40-5 -^ 8 inches 

 (length of strap acting at c E c) =: 5- &c. 1 was then clearly convinced that the strap B, which had been increased from 2 to 4 inches 

 broad, demanded a breadth of 5 inches to render it capable of producing an effect upon E proportional to that produced by A upon C. 



In some instances straps thus proportionate may require to be of an unsightly breadth, but then is it not evident that in such cases, the 

 first determined strap is broader than necessary ? However, I am of opinion that in many cases of ordinary occurrence, the broad straps 

 are more suitable to occupy the situations of the narrow ones, and vice versa. In conclusion, I trust, supposing what I have here said to 

 be successful in conveying my meaning, that those whose curiosity may lead them to give the subject a little consideration, will with my- 

 self agree, that the breadths of straps in a combination ought no/, as cog wheels, to be proportionate to their velocity; but that their 

 breadths are dependent oa the amount of their surface acting upon the smaller pulleys, in proportion inversely to their velocities. 



I am. Sir, in every respect, 



Your humble servant, 

 Vesper. 



Lads, January 11, 1842. 



ON ARCHITECTURAL PRECEDENT. (TO H. S.) 



The remarks on architectural precedent by H. S. were particularly 

 pertinent, and would have been perfectly clear, had the concluding 

 paragraph been omitted; but the opinion there expressed is very far 

 from self-evident, and will certainly require further explanation. Our 

 endeavours should always be to surpass our predecessors in the scale 

 of excellence, not by undervaluing them, while we remain stationary, 

 to prove that they are inferior to ourselves; and something more is 

 surely required than a neat antithesis, to depreciate the character of a 

 people whose works, whether of art or literature, have been the 

 delight of men of taste for more than 2,000 years. 



The system of classical education 50 years ago might well keep up 

 the prejudice against Gothic architecture; but that is now in a great 

 measure done away, and the evil of architectural precedents is as 

 great as ever, and influences Gothic quite as much as Grecian. There 

 must therefore be some other cause for the evil than that cited by H. S. 



Every ancient building is useful in the education of an architect, as 

 exhibiting what has been produced by the genius of our predecessors, 

 and what method of proceeding circumstances have induced them to 

 adopt. Grecian architecture affords specimens of carefully-studied 

 and accurately-beautiful proportions ; the grandeur produced by sim- 

 plicity of plan and construction, and the careful treatment of detail : 



and the excellence of their sculpture, which no one has ever questioned, 

 indicating a superiority in one branch of art, demands from us a more 

 careful examination of their architecture than a superficial view might 

 first appear to render necessary. Roman exhibits the effect of 

 magnitude, combined with greater multiplicity of parts, increased com- 

 plexity of plan, and skill in construction. In Gothic we see a rather 

 less complicated plan — the extreme of constructive skill — and a gran- 

 deur of effect united with a richness and delicacy of detail combining 

 in this respect the excellencies of the Greeks and Romans. In the 

 same manner something may be learned from every style, Egyptian, 

 Indian, Mahometan, &c. From these studies the architect discovers 

 the principles of taste, and the power of criticising not only the works 

 of others, but what is more difficult, his own. At the same time that 

 he is profiting by their experience he must exercise bis invention by 

 constant practise, and he need not fear the greatest exuberance of 

 fancy, if restrained by good taste, being only dangerous where it ob- 

 tains the mastery over judgment. Beyond this, as materials, which 

 are the common property of every body to cut and remodel, or copy 

 with such variations only as indicate that while we assume the manner 

 we entirely disregard the spirit, they are absolutely worse than 

 useless. This, however, is the abuse, and should not discourage a 

 judicious use of them. 



J. L. 



