179714 ⎘
Apparatus for measuring unknown time intervals by mechanical means using a mechanical oscillator running only during the time interval to be measured, e.g. stop-watch
Sub-classes:Systems and methods for encouragement of data submission in online communities
#2Systems and methods for encouragement of data submission in online communities
#3Chronograph mechanism
#4Systems and methods for encouragement of data submission in online communities
#5Stop watch including a time indicator