94 ENGLISH MEN OF SCIENCE. [CHAP.
always found time to study and make my own instruments. Later on, my studies and scientific work were always accomplished after business hours ; and it was generally my habit to commence work after dinner, and to work in science until two, three, or four in the morning, and to begin work in business again at nine. I never thought of rest if I had anything in band of interest.
"Father-Remarkably active and capable of sustaining an amount of bodily exertion which would have destroyed the health of most men ; for example, I have known him sustain great fatigue for eighteen hours out of the twenty-four for months at a stretch. A great walker. In mind-Of indomitable activity ; a great reader ; always at work in applying discoveries in . . . . to the arts ; an untiring worker in anything he undertook. Mother-Busily active ; great and rapid reader of current literature-perhaps had read almost every book of interest in fiction which appeared."
37. " Used to work all day at business, and one half or three-quarters of the night at science.