the film or plate in photography.

Decimeter. The length of one-tenth of a meter in the metric
system.

Decameter. The length of ten meters in the metric system.

Defective. Not perfect; wrong in some particular.

Diaphragm. A plate, such as used in a telephone system, to receive
and transmit vibrations.

Dissolving. To change from a solid to a liquid condition.

Division plate. A perforated plate in a gear-cutting machine, to aid
in dividing the teeth of a wheel.

Dispelled. To drive away or scatter.

Disinfectant. A material which will destroy harmful germs.

Diametral pitch. The number of teeth in a gear as calculated on the
pitch line.

Dimension. Measurement; size.

Ductility. That property of metal which permits it to be drawn
out, or worked.

Dividers. An instrument, like a compass, for stepping off
measurements, or making circles.

Diverge. Spreading out from a common point.

Drift. A cutting tool for smoothing a hole in a piece of
metal.

Duplex. Two; double.

Dynamite. An explosive composed of an absorbent, like earth,
combined with nitro-glycerine.

Dynamometer. An instrument for measuring power developed.

Eccentric. Out of center.

Echoes. The reflection of sound.

Effervesce. The action due to the unity of two opposite chemicals.

Efficiency. The term applied to the quality of effectiveness.

Ellipse. A form which is oblong, or having a shape, more or
less, like the longitudinal section of an egg.

Electrolytic. The action of a current of water passing through a
liquid, and decomposing it, and carrying elements
from one electrode to the other.

Elasticity. The quality in certain substances to be drawn out
of their normal shape, and by virtue of which they
will resume their original form when released.

Embedded. To be placed within a body or substance.

Emerge. To come out of.

Emphasize. To lay particular stress upon.

Emery. A hard substance, usually some of the finely divided
precious stones, and used for polishing and grinding
purposes.

Enormous.