Illustration: FIG. 6. (‡ WIRE GAUGE.)

The sizes of wires are ascertained by a small instrument called a

“gauge,” which is a plate of steel with an opening diminishing to

a point in it, and marks on the sides corresponding to the distance

the wire will pass down the notch (fig. 6).

The Boy's Book of Industrial Information · 第 120 / 388 题