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Thus R = 144/15 = 9.6 ohms . . . I needed to create a 9.6 ohm heating element out of nichrome. Now, I also wanted to go around the telescope tube a fixed number of times - not 1.25 turns, not 3.6 turns. Upon measuring my scope circumference, it was 37", or 3.08 feet. So I had to find a nichrome wire with a characteristic resistance such that one, two, or three loops of 3.08 feet would provide just over 9 ohms of total resistance. I thought that to heat evenly and "gently", two loops would be better than one, since it would transfer the heat over a larger surface area and reduce the "point" wire temperature. As it turns out, this was a good idea, since part of the wire is not in contact with a good thermal conductor.The nichrome I used was from Lile Engineering, who offer it at a very reasonable cost and were very helpful with suggestions on end point terminations. In the end, I opted to use nichrome with a characteristic resistance of 1.47ohms/ft - which resulted in a total resistance (Rh) of 9.06ohms. Bingo. Close enough for me.

When you blow on a small incandescent wire you can cool it enough that it ceases to emit light.
Material
Nichrome wire, 30 cm, 1 foot, of 32 gauge
two alligator clip leads
A Variac or other AC power supply capable of supplying 24 volts at 1 amp.
A plug to connect the power supply to the alligator clips.
A ring stand
Two test tube holders for the ring stand
a magnet the larger and more powerful the better.
Assembly
Build the nichrome wire holder:
Attach the test tube holders to the ring stand about 24 cm apart.
Squeeze one alligator clip in the upper holder.
Clip the alligator clip to the nichrome wire.
Clip the other alligator clip to the bottom of the wire.
Use the bottom test tube holder to gently hold the bottom alligator clip.
Optional, you could create your own wire holder using PVC tubing.