Page:How and Why Library 409.jpg

 watchmaker, with a magnifying glass screwed into one eye, has to pick up the one hundred and fifty separate parts, some with magnets, and fit them all together into a compact circle that will slip right into a tiny gold shell of a case. And he has to do all this so the little machine will keep perfect time. No spring must be too short or too long, no screw too tight, no wheel or tooth must rub another.

When your watch runs down you ask someone the time, or you set it by a public clock. In watch factories every watch is set and regulated by the fixed stars. The sun is not the best time-keeper. It goes fast or slow, or it seems to do so. But the earth turns around and around in the same space of time, day after day. As it turns, certain fixed stars, or very distant suns that appear as stars, come into view at the same instant each night. In a big watch factory an astronomer has a telescope set so that these stars seem to pass across the lens. Really, watches are set by the earth we live upon. The hour-hand of a perfectly-timed watch goes twice around the dial in exactly the same time that it takes our dear old earth to turn over once on its axis. The heart of the big earth and the heart of the little watch beat together.

Isn’t that very wonderful? And don’t you think Old Father Time ought to carry a little bunch of stars?