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1932 - new lighted pointer assists in lectures and blackboard demonstrations


CD 2478055 E&MP12.034

Electric Appliances & Apparatus

April 30, 1932

To assist in lectures and blackboard demonstrations, Westinghouse research engineers have devised a novel and effective aid consisting of a lighted pointer. By placing this spot of light at the center of interest of the diagram, the speaker is able to focus the attention of his audience on the point of interest emphasizing in relief the area being discussed. Also, when used with a colored light, it may be used with lanter slides.

The pointer is easily made and may be built by anyone having the need of a similar device. It is entirely self contained consisting of a standard flashlight, a sectional steel fishing rod, and some small wire. The flashlight proper is the handle of the pointer with the bulb placed at the end of the fishing pole, and connected to the battery through the hollow pole. The light is used as desired by pressing the flashlight switch in the handle.

Captions for Illustrations:

Novel flashlight pointer used at Westinghouse to animate blackboard talks.

Closeup showing the arrangement of the lamp in the end of the flashlight pointer used at Westinghouse to aid in focusing the attention of the audience on the blackboard where desired.

additional text found:

ELECTRIC POINTER OUSTS FISHPOLE FROM LECTURER’S EQUIPMENTSchenectady, April -- College professors no longer need to take their old-time fishpole to class when they deliver a lecture. Now they can “pack” an electric gun, that shoots little arrows of light onto a motion picture or lantern slide screen. In fact, the lecturer can sit in the second or third row in an auditorium and by the simple expedient of pressing a switch project a white arrow upon any part of the screen he desires without moving from his seat or getting himself between the audience and the screen.

The electric pointer, developed by F.A. Benford, of the General Electric research laboratory in Schenectady, consist of a nozzle very similar to that found on a garden hose, except that it is a little longer. Made of aluminum, it is light in weight, and to its handle is attached a lead which can be plugged into any convenient outlet. In the far end of the pointer is an objective lens, halfway toward the handle a condensing lens, and between these two a diaphragm, or small slide, with the arrow on it.

A 125-watt lamp is used in the device to obtain the intense light necessary, for the arrow can be seen even when projected against the white of the slide. A small switch on the handle of the pointer turns on the arrow, and a push button informs the operator of the projector when the slides shall be changed.

Thanks to the electric pointer, the lecturer can see his own slides from a suitable distance -- probably for the first time in the history of lecturing.

Original Caption by Science Service
©General Electric

National Museum of American History


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