Only the "drum" type of armature is treated here.

This refers to continuous-current dynamos only.

The Robertson.

This resembles the upper part of the rudimentary water injector shown in Fig. 15. The reader need only imagine pipe B to be connected with the train pipe. A rush of steam through pipe A creates a partial vacuum in the cone E, causing air from the train pipe to rush into it and be expelled by the steam blast.

Glazebrook, "Light," p. 157.

Glazebrook, "Light," p. 157.

Galileo was severely censured and imprisoned for daring to maintain that the earth moved round the sun, and revolved on its axis.

For a full account of Animated Pictures the reader might advantageously consult "The Romance of Modern Invention," pp. 166 foll.

Tyndall, "On Sound," p. 75.

A Broadwood "grand" is made up of 10,700 separate pieces, and in its manufacture forty separate trades are concerned.

Twelve notes higher up the scale.