Referring to Dr. Jones's paper in the last number of this Journal, Mr. Townsend writes: —

Electric Lighting Engines.—Statistics taken during the last five years show (as pointed out by Dr. Jones, p. 761) that high-speed engines coupled direct to dynamos and with improved multitubular boilers, are coming into favour, and prove that their cost of generating current is nearly 10 per cent. lower than with slow-speed engines and belt-driven dynamos—especially when the engines and dynamos are of 50 horse-power and upwards.