Bulb

The bulb is the glass portion of a lamp. Despite popular belief, it is not the entire lamp. This is often a sensitive point with many theatre electricians. In most lamps used in theatre, particularly quartz lamps, it is very important not to touch the bulb with your bare fingers. The oil from your fingers causes the lamp to heat unevenly, which can cause premature failure of the lamp, usually in the form of a loud bang. The typical result is either an explosion of the wall of the lamp, or simply sever deformation. A blemish in the shape of a linger is goiod way to get in trouble with your master electrician.

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Bulb (?), n. [L. bulbus, Gr. : cf. F. bulbe.]

1. Bot.

A spheroidal body growing from a plant either above or below the ground (usually below), which is strictly a bud, consisting of a cluster of partially developed leaves, and producing, as it grows, a stem above, and roots below, as in the onion, tulip, etc. It differs from a corm in not being solid.

2. Anat.

A name given to some parts that resemble in shape certain bulbous roots; as, the bulb of the aorta.

Bulb of the eye, the eyeball. -- Bulb of a hair, the "root," or part whence the hair originates. -- Bulb of the spinal cord, the medulla oblongata, often called simply bulb. -- Bulb of a tooth, the vascular and nervous papilla contained in the cavity of the tooth.

3.

An expansion or protuberance on a stem or tube, as the bulb of a thermometer, which may be of any form, as spherical, cylindrical, curved, etc.

Tomlinson.

 

© Webster 1913.

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Bulb, v. i.

To take the shape of a bulb; to swell.

 

© Webster 1913.