reproducer of the phonograph. Also a watch case

[Illustration: The Long-Distance Phonograph]

receiver, R, which fasten to the horn. These parts may be
purchased from any electrical-supply house. Connect two wires to
the transmitter, running one direct to the receiver, and the other
to the battery, thence to a switch, S, and then to the receiver.
The more batteries used the louder will be the sound produced by
the horn, but avoid using too much battery or the receiver is apt
to heat.
--Contributed by Wm. J. Farley, Jr., Camden, N. J.

** How to Make a Telescope [108]

With a telescope like the one here described, made with his own
hands, a farmer boy not many years ago discovered a comet which
had escaped the watchful eyes of many astronomers.

First, get two pieces of plate glass, 6 in. square and 1 in.
thick, and break the corners off to make them round, grinding the
rough edges on a grindstone. Use a barrel to work on, and

[Illustration: Homemade Telescope]

fasten one glass on the top of it in the center by driving three
small nails at the sides to hold it in place. Fasten, with pitch,
a round 4-in. block of wood in the center on one side of the other
glass to serve as a handle.

Use wet grain emery for coarse grinding. Take a pinch and spread
it evenly on the glass which is on the barrel, then take the glass
with the handle and move it back and forth across the lower glass,
while walking around the barrel; also rotate the glass, which is
necessary to make it grind evenly. The upper glass or speculum
always becomes concave, and the under glass or tool convex.

Work with straight strokes 5 or 6 in. in length; after working 5
hours hold the speculum in the sunshine and throw the rays of the
sun onto a paper; where the rays come to a point gives the focal
length. If the glass is not ground enough to bring the rays to a
point within 5 ft., the coarse grinding must be continued, unless
a longer focal length is wanted.

Have ready six large dishes, then take 2 lb. flour emery and mix
in 12 qt. of water; immediately turn the water into a clean dish
and let settle 30 seconds; then turn it into another dish and let
settle 2 minutes, then 8 minutes, 30 minutes and 90 minutes, being
careful not to turn off the coarser emery which has settled. When
dry, turn the emery from the 5 jars into 5 separate bottles, and
label. Then take a little of the coarsest powder, wetting it to
the consistency of cream, and spr