In message <970107012613_1990957654@emout01.mail.aol.com>, Shel Michaels writes
:
>I never realized tempcos were so high!  Means that you should have observed a
>resistance change on the order of eight ohms or so.

        Well, 3 to 4 Ohms is fairly close when one considers the unknowns.
I don't know how much ambient heat transfer there is between the lamp
filaments and the outside air.  I would think that since the bulb is mostly
evacuated, the filament is somewhat insulated from the world.

        Any slight change in the formulation of the filaments would probably
also make a big difference in the resistances one would read.

Martin McCormick