At 10:53 PM 2/12/98 -0600, you wrote:
>For a handy reference, go to your local electrical wholesale house and
>ask for a GE lighting catalog;  you'll find those mysterious 15W bulbs
>as well as clear; even a bulb with a left-hand thread.

The bulbs (lamps) with left-handed threads were (or are) used in the New
York City Subway system to discourage theft.

The original bulbs used carbon filaments. When was tungsten introduced?

A story regarding bulbs and electricity:
Many early electric distribution systems (especially in cities where the
distribution lines were short) used Direct Current (AC travels further). No
flickering there.  During the big black-out in NY during 1965(?) DC was
still being distributed in New York City. The lecture room I was in at the
time used both AC and DC. The slide projectors ran on DC and when the power
grid failed the DC power stations lost their voltage slowly. When the AC
failed all the AC lights had been turned off and the only light was from
the DC projectors whose light faded into nothing over the course of about a
half hour.

r.baron

=============================================
Town Meeting on Copyright and Digital Images:
November 26, Toronto with College Art Assn.
http://www.pipeline.com/~rabaron/ttm/TTM.htm
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Robert A. Baron
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