Describes the Johns Hopkins chronoscope which is the second model of which 9 instruments have been made. The advantages of this chronoscope are that: (1) it can be operated with practically no noise (2) it requires no winding (3) the dial is large and easily read; and (4) the hand is readily set back to zero, avoiding the necessary subtraction. (PsycINFO Database Record (c) 2006 APA, all rights reserved)