An experiment concerning the efficiency of the human body under varying conditions of temperatures has recently been completed at the Harvard Public School of Health. The detailed results of the research work carried out by C. P. Yaglou are soon to be announced.

In this experiment the electrical energy produced by a man riding a bicycle was measured. It was discovered that man is at his highest physical efficiency when he is work-in a temperature of 70 degrees. Under such conditions 24 per cent of his food energy is given to mechanical work.

Under higher or lower conditions of temperature his efficiency decreases. It was discovered, for example, that in a temperature of 110 degrees man's efficiency is only 18 per cent, a reduction of 6 per cent over his efficiency at 70 degrees. This is the condition in many branches of industry, as in steel mills and glass works. It is believed that further work in this line, and adaptation of its results to practical problems will prove of great value in such branches of commerce.