ich deaf people are enabled to read speech more or less correctly by
observing the motion of the lips. The family moved to Canada in 1872,
and Alexander Bell came to Boston, where he soon became widely known as
an authority in the teaching of the deaf and dumb. The reproduction of
the human voice by mechanical means interested him deeply, and his study
of the construction of the human ear, with its drum vibrating in
response to sound vibrations, gave him the idea of a vibrating piece of
iron in front of an electric magnet. He was, however, very poor and had
no money to expend in experiments--so poor, indeed, that when attacked
by illness, his hospital expenses were paid by his employer, and so
friendless that during his illness no one visited him except two or
three pupils from his school.

He persevered with his experiments, with such rude apparatus as he could
make himself, and the first Bell telephone was brought into existence
with an old cigar-box, two hundred feet of wire, and two magnets from a
toy fish-pond. In an improved form, it was shown at the Centennial
exhibition of 1876, where Sir William Thomson pronounced it "the
greatest marvel hitherto achieved by the electric telegraph." As is
always the case, the public was slow to appreciate the importance of the
invention, and as late as 1877, Bell was unable to secure $10,000 for a
half interest in the European rights. The rapid growth of the business
in this country is almost without a parallel in history, and no
invention has added more to the convenience of modern life.

* * * * *

A distinguished scientist one day asked the late Clerk Maxwell what was
the greatest scientific discovery of the last half century, and Maxwell
answered without an instant's hesitation: "That the Gramme machine is
reversible." Probably the whole scientific world will agree with him,
for that discovery meant that power will not only produce electricity,
but that electricity will produce power. Let us see how that has been
applied. Falling water is one of the most powerful agents in the world,
and at a great waterfall like Niagara, millions of horsepower go to
waste every day. So at the foot of Niagara, great power-houses have been
built where the power of the water is converted into electricity. The
electricity is conducted along wires for hundreds of miles to the great
industrial centres, and there converted back again into power. In other
words, th