M. C. F., St. Louis, writes:

" Do you know of any way in which I can find out the temperature of the water in the pipes of a hotwater job without breaking the pipe line to put in a thermometer cup ?"

[Place the bulb of a thermometer against the pipe and put a lump of putty over the bulb so as to press the bulb against the pipe. You might further prevent radiation from the bulb by putting cotton waste outside of the putty. String can then be wrapped about the whole so as to hold it in position. If this is carefully done the thermometer will register within 1 degree of the temperature of the water in the pipe.]