Book 3 — Timing Pointer on Watch Crystal

Working in a photo-print finishing plant where often several jobs need attention and accurate timing, all at the same time, I find a pointer on my watch crystal a great help. The crystal was loose enough to permit turning it. I glued a three-cornered piece of black paper to the under side of the crystal at the edge. When a batch of prints is placed in a bath, the pointer is set 15 minutes ahead of the minute hand. When the latter reaches the pointer, it reminds me to remove the prints. After placing a batch of films in the developing tank, I set the pointer ahead of the minute hand the required time for developing, placing the watch in view, to see readily when the time is up.—A. J. Viken, Waterloo, Iowa.