HOW TO MAKE A TELEPHONE.
HELLO! Hello! What is it you say? You can really make a telephone? What
fun! How far will it work? You think it can be heard a long distance?
Very good. Could we manage to construct such a one? How, pray tell us?
The answer which came back over the line we give in a more concise
form, as follows:
The best way to make a simple telephone is to procure two round,
medium-sized tin baking-powder boxes, and remove the bottoms with a
pair of pinchers; then soak two pieces of Whatman’s drawing-paper, or
any other strong paper, in a basin of water for a few moments, and when
thoroughly wet take them out and place one smoothly over the end of
each box. Fasten these down by winding a waxed cotton twine securely
over the paper and box, and tying it tightly (Fig. 137). This done,
allow the drums to become wholly dry, when they should be firm, even,
and without wrinkles. Next cut away that portion of the paper which
stands out, frill-like, beyond the string, and paste a narrow strip of
paper around over the twine (Fig. 138). Wax a piece of string of the
desired length, and with a large needle or pin carefully punch a hole
in the centre of each drum; thread one end of the waxed string through
one of the holes and make a large knot in the end, then cautiously pull
the string until the knot rests on the inside surface of the paper.
Connect the other box to the string in like manner, so that the twine
will have a box fastened on each end.
[Illustration: _Fig. 137_]
[Illustration: _Fig. 138_]
[Illustration: _Fig. 139_]
The telephone is now ready for use; and if the distance is short, the
line may be stretched taut from point to point. But should the space be
great, supports will be needed and loops must be made of the twine and
fastened at intervals on trees, corners of the houses, or any available
points, with the connecting cord passed through these loops (Fig. 139),
which act as supports. Keep the course of the waxed string as straight
as possible, and, as far as practicable, avoid sharp angles. This
style of telephone we know, from personal experience, works perfectly
at the distance of fifty yards, and doubtless it will do as well when
the line is stretched much farther. Be particular, in selecting the
tin baking-powder boxes, to have them round and even; if they are old
and battered the experiment may not prove satisfactory. We find the
telephone very useful and convenient, besides affording any amount of
amusement and fun; with its aid we converse with acquaintances, even
though they be at a distance. The friendly little instrument carries
the voice all along the slender line to the very ears of our best
friend, and we can chat away as freely and almost as easily as if side
by side. What a comfort to be able, when seated in your own room, to
listen to the voice of some companion, living perhaps blocks away, and
it is such a pleasure, too, to have questions answered immediately,
which is impossible in communications made by letter. Nor is this a
pleasure to be enjoyed at rare intervals, for as long as the telephone
lasts it can be used at any time for a short or long talk, as one may
feel inclined. The consultations, the plans, the sport, and merriment
to be had with the telephone can scarcely be appreciated by one who is
not the happy possessor of such an instrument.
[Illustration: Listening.]
When the weather will not permit of a walk or a visit, the telephone
brings us, if not face to face, at least within speaking distance of
those to whom we desire to talk.
There are many other easy methods of making telephones. They can be
manufactured as described without waxing the string, or the boxes may
be used unaltered, in which case the tin bottoms serve as drums, and
the holes for the string are made in the centre of each by driving a
small tack through. With these instruments the voice cannot be sent a
great distance, but when only a short line is needed they succeed very
well.
More complicated telephones are made with the drums of bladder and the
line of soft, flexible wire. Though good and serviceable, they are more
difficult to make and require more time and labor.
[Illustration: Speaking.]
The two beef-bladders used for such a telephone must first be blown up,
tied, and left about thirty hours, or until they are stretched, but not
dried. When in proper condition, cut off the necks and portion of the
ends, then soak them in warm water, and they will become very pliable
and light in color. Having previously prepared two square pieces of
board by very carefully cutting out a perfect circle in the centre of
each, about as large as a medium-sized pie-pan or a tea-plate, place
the bladders smoothly but not tightly over the openings, allowing the
outside of the bladder to come on the bottom, and fasten it all around
the circle, a little distance from the edge, with tacks so driven in
that they may be easily removed.
Try the drums with your finger; if they stretch evenly they are
correct, if they wrinkle, change them until they stretch perfectly
smooth. Then tack a piece of firm tape securely around the edge of
the circle, and cut off the bladder reaching beyond the tape. Next
fasten four feet of soft, flexible wire to a large-sized gutta-percha
button by threading it through the two opposite holes in the centre of
the button; pass the other end of the wire through the middle of the
bladder, bringing the button flat against its surface.
After attaching a weight of about seven pounds to the end of the wire,
place the drum in the sun until perfectly dry. Proceed with the other
in the same manner, and when both are well dried, fasten one on each
end of the line and attach the drum-wires to the principal wire by
loops; then stretch it firm and tight. This telephone will also need
loops for supports, which should be of wire. When the instrument is
carefully and properly made it will carry the voice three or four miles
or more, giving every word and tone distinctly and clearly.
[Illustration]