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Popular Mechanics Co.

"The Boy Mechanic: Volume 1 700 Things for Boys to Do"


If desired, the string may be stretched back and forth under the
roof several times or drawn through any place that is in danger of
fire.
--Contributed by Geo. B. Wrenn, Ashland, Ohio.

** How to Make a Small Electric Furnace [48]
Take a block of wood and shape into a core. One like a loaf of
bread, and about that size, serves admirably. Wrap a layer of
asbestos around it and cover this with a thin layer of
plaster-of-paris. When the plaster is nearly dry wind a coil of
No. 36 wire around it, taking care that the wire does not touch
itself anywhere. Put another course of plaster-of-paris on this,
and again wind the wire around it. Continue the process of
alternate layers of plaster and wire until 500 ft. or more of the
latter has been used, leaving about 10 in. at each end for
terminals. Then set the whole core away to dry.
For a base use a pine board 10 in. by 12 in. by 1 in. Bore four
holes at one end for binding-posts, as indicated by E E. Connect
the holes in pairs by ordinary house fuse wire. At one side secure
two receptacles, B B, and one single post switch, C. Place another
switch at I and another binding-post at F.


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