A Description in non-technical Language of the diverse and wonderful ways in which chemical forces are at work and of their manifold application in modern life.
By permission op
7 he United States Metallic Packing Co., Ltd., Bradford
A Portable Drill
, Hr6 *T?^e'n workman can drill holes in massive plates of iron by mechanical
th* k “e wo[kman in the above illustration is using a portable drill upon
le ooiler of a locomotive. He merely controls the drill, which is driven bv
an electric motor. 3