In a very excellent article in the Journal of the Franklin Institute, by B. F. Isherwood, Chief Engineer, U. S. N., it appears that the Collin's steamers use anthracite on the voyage to Liverpool, and Welsh coal, also an anthracite, on the return voyage. The Welsh coal and Pennsylvania are nearly of the same value for raising steam. The consumption of coal in the Arctic in 24 hours is 8548 tons, and no less than about Si lbs. per horse power per hour. The number of pounds of water evaporated with 1 lb. of coal is 7'539 lbs. by the anthracite, and 7 652 lbs. by the Welsh coal. The initial pressure of steam in the cylinders per stroke is 13 85 lbs; this is cut off at 4 feet 4 inches stroke, and with the vacuum the mean effective pressure on the pistons per square inch is 19 lbs.