Richter used Esterline Angus recorders to measure the "hands" of his rat's clock. The following photographs demonstrate the continuous activity pen recorder; cutting the recordings into individual strips for individual activity cages; pasting the strips onto a large square of cardboard in lines showing the day's activity for a given rat (using waxpaper and a hot iron); recording of the other hands of the wheel, such as water intake, food intake, weight, and vaginal cells; and transferring these numbers to the record book and to the chart for each rat that was kept throughout its life.(1)
1. Personal communication from James B. Wirth, M.D., Ph.D., to Nancy McCall, 6 February 1989.
Description of the Data
to and Use of Richter's Data