MECHANICS AND USEFUL ARTS. 17 



seventy miles, and water for thirty miles, and is arranged to run with 

 either end first. It is intended to run with light trains on a short 

 branch line. London Mining Journal, March 9. 



COMPARATIVE VALUE OF COAL AND WOOD FOR LOCOMOTIVES. 



A REPORT on some experiments mads on the Boston and Maine 

 Railroad, for the purpose of testing the relative values of anthracite 

 coal and different, kinds of wood for fuel in locomotives, has recently 

 been published by the New England Association of R,ailroad Super- 

 intendents. The engines used were the "Coaler," built by Winans 

 of Baltimore, and the "New Hampshire,'' a wood-burning engine, 

 built by Hinckley & Drury of Boston. The experiments were con- 

 ducted by Messrs. Slade and Currier. The results obtained are as 

 follows : The average quantity of station-wood required to evaporate 

 3,500 gallons is 3.45 cords; average quantity of anthracite coal, 2.15 

 tons. 215 tons of coal are therefore equal to 345 cords of station- 

 wood, or one ton of coal equals 1.6 cords of wood. The average cost 

 of fuel for carrying 15,000 tons of freight one mile, when the trips 

 are over the entire road, is, for wood, as shown by nine trips, $14.04; 

 for coal, as shown by seven trips, $ 12.70. Difference in favor of 

 coal, $ 1.34. When the engine runs only between Boston and Haver- 

 hill, $ 1.41 is to be added to the cost of wood, thus increasing the dif- 

 ference in favor of coal to $2.75. Comparing those trips in which 

 the engines are on a par as regards the evaporation of water, the aver- 

 age cost of evaporating 3,500 gallons is, with wood, $ 12.44, with 

 coal, $11.26. Difference in favor of coal, $ 1.18. Additional cost 

 of wood, if run only between Haverhill and Boston, $ 1.41, increasing 

 the difference in favor of coal per day to $ 2.59. Comparing those 

 trips which put the engines on a par as regards the size of the load, 

 the average cost of carrying 15,000 tons of freight one mile is, with 

 wood, $14.92, with coal, $11.84. Difference in favor of coal per 

 day, $3.08, or, if run between Haverhill and Boston, $4.49. The 

 average cost of wood, when the trips are over the entire road, is $3.63 

 per cord ; when from Boston to Haverhill and back, $4.08. Cost of 

 coal, $5.25 per ton. As regards speed, that of the Coaler on an av- 

 erage is 14.3 miles, of the wood engine 14.1 per hour. Difference in 

 favor of coal, .2 of a mile. The coal left in the Coaler after the trip 

 is finished is considered as balancing the wood used in kindling. 



The general result is, " that anthracite coal used for fuel in loco- 

 motives on railroads, where heavy trains are run, is superior to wood 

 in point of economy. 



" 



FORM OF RAILWAY AXLES. 



AT the meeting of the London Institution of Civil Engineers, on 

 March 26, Mr. Thorneycroft detailed a series of experiments which 

 he had made upon the strength of railway axles. His conclusions 



* See Annual of Scientific Discovery, 1850. p. 33. 

 o * 



