84 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



extending from 1863 to 1871, with their uniform results proving 

 either higher powers in combination, or the incorrectness of the 

 generally accepted formula, are not accepted as I'eliable. 



For information and figures, giving us the results of continued 

 experiments, enabling comparison to be made between the evapo- 

 rative duty of Pennsylvania hard and soft coals, our thanks are due 

 to T. N. Ely, General Superintendent Motive Power, Pennsylvania 

 Railway, and to F. E. Wootten, General Manager of Philadeliihia 

 and Reading Railway. 



On the Pennsylvania Railway, for local passenger trains, it takes 

 to haul one coach per mile, 10.44 lbs. of soft coal and 13.85 lbs. of 

 hard coal, being an increased consumption of 30 per cent, of hard 

 coal, to do exactly the same work. 



On through passenger runs, per car mile, 8.64 lbs. of soft and 

 11.55 lbs. of hard, an increase in consumption of 29 per cent. The.se 

 figures are reliable — under the given conditions, and with ordinary 

 proportions of fire-grate — being averages covering four months' work, 

 and on the through runs, with five engines burning each class of fuel. 



If, however, the boiler is arranged so as to give several hundred 

 per cent, increase in fire-grate area, the actual difference in duty per- 

 formed has been reduced by Mr. Wootten to nine-tenths of a pound 

 of water evaporated per pound of fuel, hard coal recording 6.1 lbs., 

 and soft coal 7 lbs. Thus, it requires almost 15 per cent, more hard 

 coal to do the same evaporative work, even with this excessive 

 increase in grate surface. 



It should not, in our consideration, be forgotten, that the first cost 

 of the locomotive type of boiler to consume hard coal is increased 

 from 10 to 25 per cent, dependent on the excess of grate area allowed ; 

 and its total lease of life, when using hard coal, is variously stated at 

 from eight-tenths to six-tenths of that of a boiler using soft coal, but 

 in all other respects doing similar daily work. 



No doubt there are boilers in which hard coal will give a higher 

 evaporative duty than in locomotive practice, as also will soft coal ; 

 but the circumstances controlling the test must always be fully con- 

 sidered in making any direct comparison of figures, and, if possible, 

 the conditions made equal and similar, otherwise it is possible for 

 peat, used under favouring circumstances, to give a higher evapora- 

 tive result per pound than coal used under unfavourable conditions. 



