MECHANICS AND USEFUL ARTS. 39 



cylindrical part of the boiler could be filled with tubes, as the longitu- 

 dinal stays could be removed. By this arrangement 225 tubes, of 2 

 inches external diameter, could be used, the shell being 3 feet 8 inches 

 in diameter and 10 feet long. The total heating surface of the fire- 

 box is 80 feet, and of the tubes 1,177. This arrangement involves 

 the necessity of keeping the boiler full of water, and it then becomes 

 necessary to provide a separate steam-chamber. This consists of a 

 cylinder 18 feet long and 20 inches in diameter, fixed over and parallel 

 to the cylindrical part of the boiler. This tube has a cubic capacity of 

 28| feet, and has two communications with the boiler ; it is proposed 

 that the water shall occupy about one fourth of the tube, leaving 

 the remaining 21 cubic feet for steam. Some discussion took place 

 upon this plan, and it was objected that there would be a tendency 

 to "prime" in such a boiler, but it was also suggested that this 

 might be remedied by having a more continuous communication be- 

 tween the generator and the cylinder. 



ANTHRACITE COAL IN LOCOMOTIVE ENGINES. 



MR. GEORGE W. WHISTLER, a son of the late distinguished engi- 

 neer, has made a very valuable report on the use of anthracite coal In 

 locomotives, containing the results of experiments and observations 

 made by him on the different kinds of fuel in three different varieties 

 of locomotives on the Reading, Pa., Railroad. The three locomotives 

 were an anthracite coal one, built by Ross Winans of Baltimore, a 

 condensing engine, the Novelty, also burning anthracite coal, and the 

 ordinary wood engine. He records 17 trips of the Baltimore coal en- 

 gine, 5 of the Novelty, and 3 of the wood-burning engine; the quan- 

 tity of fuel reckoned as consumed is always the difference between 

 that taken at one end of the road and that remaining at the other. 

 The Baltimore engines, in their 17 trips from Richmond to Pottsville, 

 and xice versa, consumed 79.9 tons of coal, equal to an average of 4.45 

 tons per trip up, and 4.95 tons per trip down, or 9.4 for the round trip. 

 The average load down was 90 cars, with 450 tons of coal. The coal 

 used was the "Forest Improvement," much of which is fine, with 

 dirt intermixed, so that the waste amounts to about half a ton per trip; 

 but Mr. W. deducts 5 per cent, from the gross weight, which leaves 

 exactly 76 tons for the 17 trips, and 9 tons for each round trip. The 

 Novelty condensing engine consumed in 5 trips 28.1 tons, equal to 

 5.62 tons for every up trip, 5.63 for the down one, and 11.25 for the 

 round trip, or, deducting 5 per cent. 10.7 tons for the round trip. 

 The average load down was 75 cars, with 375 tons of coal. The In- 

 diana wood engine consumed 7 cords for every up trip, and 7.37 for 

 the down one, making the wood used per round trip 14.37 cords. The 

 average load down was 88 cars, with 440 tons of coal. The return 

 load was always about one-third of the gross weight of the train 

 brought down. Wood costs $4 per cord, and coal $2.75 per ton of 

 2.240 pounds. Mr. Whistler, who is perhaps somewhat prejudiced, 

 says of the Novelty engine, " I could but agree in the opinion gene- 

 rally entertained and expressed, of its entire impracticability." 



