48 ANNUAL OF SCIENTIFIC DISCOVERY. 



warm : therefore, whenever it is possible, they should not be built on the 

 outer walls of houses, such as gables. As a general rule, the grate should be 

 situated at such a position in the fire-place where it can be seen from the 

 greatest number of points in the room, and a good frontage of tire-surface 

 should always be exposed. Scientific American. 



OX THE RELATIVE VALUES OF COAL AND COKE IN LOCOMOTIVE 



ENGINES. 



In a paper on the above subject, read before the Society of Arts, London, 

 May 18:h, 18-39, by B. Fothergill, Esq., the author stated that his object was 

 to lay before the Society the results of a series of experiments which he had 

 made with coal and coke in locomotive engines, and which had led him to 

 the conclusions that coal was decidedly superior to coke in respect to heat- 

 ing power, and consequently more economical; that a plentiful supply of 

 steam could be generated by it for working engines at high velocities, and 

 for drawing heavy trains ; that coal-burning engines could be made to con- 

 sume their own smoke, and that the fire-boxes and tubes, when coal was 

 used, were found to last longer. His experiments had been conducted upon 

 the London and South- Western Railway, and were made, at the request of 

 the directors, to ascertain the value of an invention \\ hich had been pa- 

 tented by then* locomotive superintendent, Mr. Joseph Beattie, and which 

 the author proceeded to describe in detail. The contrivance consists in so 

 dividing the fire-box as to increase the amount of heating surface, and to di- 

 minish the indirect or tube surface, whilst the combustion chamber affords 

 sufficient space for the introduction of a series of fire-tiles, for the purpose of 

 retaining a portion of the heat given off from the combustion of the gases, 

 and for diffusing the unconsumed carbon, as well as effecting a complete mix- 

 ture of the air with the gases, and thereby producing a mass of flames, which 

 is brought in contact with the direct heating surface of the combustion cham- 

 ber before it enters the tubes, at the same time preventing practically such 

 an escape of smoke from the chimney as could be deemed a nuisance. In 

 addition to the practical experiments made by the author on the South- 

 Western Railway, a series of accurate analyses, with the view of ascertain- 

 ing the composition and heating power of various kinds of coke and coal, 

 had been made; and from all these investigations it appeared that a saving 

 of from 8} to about 10f Ibs. of coke per mile Avhich, of course, represented 

 a larger quantity of coal was effected by the use of coal in the patent fire- 

 box described, as compared with the quantity of coke consumed in the ordi- 

 nary engines, under similar circumstances. With regard to the durability of 

 tlie tubes, it had been found, that in the coke-burning engines, about 94,000 

 miles was the average duration of a set of tubes, whilst of the experimental 

 engines buraing coal, one had already run 181,000 miles, and the tubes were 

 still in good condition. The author, therefore, expressed a strong opinion in 

 favor of the advantages of coal over coke for locomotive engines. 



ON THE INTRODUCTION OF PRESERVATIVE SOLUTIONS INTO 



RAILWAY TIMBER. 



The following is an abstract of a valuable paper on the above subject, 

 communicated to the Journal of the Franklin Institute, Jan. 18-39, by F. 

 Hewson, C. E: 



