Draw a foot of the wire through the hole in the reel, and drive in a tiny
peg--which must not protrude inwards--to prevent it slipping. Lay the
turns on carefully, forcing them into close contact, so that the next layer
may have a level bed. On reaching the end of the layer, be equally careful
to finish it neatly before starting back again. When the wire is all on,
bore a hole as near the edge of the finishing edge as possible, and draw
the spare wire through. Then cut a strip of tough paper of the width of the
coils, coat one side with paste, and wrap it tightly round the outside to
keep the wire in place.
Note.--Insulation will be improved if every layer of wire is painted over
with shellac dissolved in alcohol before the next layer is applied.
Flatten the reel slightly with a file at the points of contact with the
baseboard, to prevent rolling.
The plunger is a tube of thin iron, 1/16 inch less in diameter than the
hole in the reel, and 1/4 inch longer than the reel. If a ready-made tube
is not available, construct one by twisting a piece of tin round a metal
rod, and soldering the joint.
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