Proceedings of the British Association. 



587 



house chimney; and small pipes of one inch diameter, at the top of 

 each room, communicated with the pipes in the gallery. This plan 

 had also been tried in the Glasgow Fever Hospital, in which the beds 

 for fever patients, &c. were fitted up with the tubes for carrying away 

 noxious effluvia. A similar plan for the ventilation of ships and 

 steamers had been introduced by Dr. Reid, by leading tubes from the 

 berths into a stove on deck, or, in steamers, into the chimney. Mr. 

 Liddell stated that the expense for a house of 60,000 cubic feet was 

 only 40 lb. of coal in twenty-four hours. 



Sir J. Robison remarked, that from his experience the plan of Mr. 

 Fleming, as far as regarded the size of the pipes, was inadequate. 



Prof. Vignoles made a communication on Straight Axles for Lo- 

 comotives. He stated that an unfounded prejudice existed in favour 

 of cranked axles, which, in his opinion, were inferior to straight 

 ones in almost every point of view. With straight axles the cranks 

 were thrown outside the wheels, which gave more room for the 

 arrangement of the working parts ; and another great advantage was 

 gained by lowering the boiler nearly fifteen inches, and thereby in- 

 creasing the safety of the engine, by placing the centre of gravity 

 nearer the rail. The original expense of the engine and of the repairs 

 was also much lessened. These advantages might be shown by a 

 reference to the Dublin Kingstown Railway. By introducing straight 

 axles and outside cranks the expenses had been greatly decreased, 

 no accident had ever occurred from breakage ; and such increase of 

 room had been obtained, that they had placed the tender underneath 

 the engine, thus fixing the centre of gravity as low as possible, and 

 dispensing with the separate tender. By this arrangement they could 

 run fifteen miles without stopping for water. He had found much 

 difficulty in introducing the straight-axled engine on this line ; and, in 

 fact, the great obstacle in obtaining a fair trial for different forms 

 of engines arose from the fluctuation in public opinion. Straight 

 axles and cranked axles, four-wheeled and six-wheeled engines, had 

 been used on different lines, not so much from the recommendations 

 of the engineer as in compliance with the opinion of the several 

 railway boards. Just now a prejudice existed against four-wheeled 

 engines, as being less safe than six-wheeled, more liable to run off the 

 line, &c. whereas he contended that the four-wheeled engine per se 

 was not open to these objections. He believed that the principal 

 advantage which could be claimed for the six-wheeled engine was in 

 the disposition of the weight on the wheels ; and a consideration of the 

 fatal accidents which had lately occurred on the London and Brighton 



