e, was invented by
Sir David Brewster in 1818. The leading principles of the toy appear to
have been accidentally discovered in the course of a series of
experiments on the polarization of light by successive reflections
between plates of glass. The invention of this now despised toy made a
tremendous sensation at the time, and the inventor was induced to take
out a patent for its protection; but he had, it appears, divulged the
secret of its construction before he had secured the invention to
himself, and the consequence was that, although "it made a hundred
shopmen rich," it brought the inventor himself but little substantial
benefit. This is explained by the fact that it was so simple in
construction, that even when made without scientific accuracy, it served
to delight as well as to amuse. So largely was it pirated, that it was
calculated that no fewer than two hundred thousand were sold in three
months in London and Paris alone. Judging by a caricature of
Williams's, published by Fores in June, 1818, and its doggerel
explanation, the toys would appear even at this time to have been made
and sold by every street boy. The satire is called, _Caleidoscopes, or
Paying for Peeping_. In it, we see the pertinacious vendors pushing the
sale of their wares upon the passengers in the streets--many of them
women. A bishop resolves to buy one because the coloured glass reminds
him of a painted window in his cathedral, another person has paid dearly
for "peeping," and discovers that while gratifying his curiosity, his
"pocket-book has slipped off with two hundred pounds in it." Williams
was a satirist of the old school, and the allusions made by some of the
vendors render this otherwise interesting satire wantonly coarse and
indelicate. Attached to this rare and curious production is the
following doggerel:--

"'Tis the favourite plaything of school-boy and sage,
Of the baby in arms and the baby of age;
Of the grandam whose sight is at best problematical,
And of the soph who explains it by rule mathematical.

Such indeed is the rage for them, chapel or church in,
You see them about you, and each little urchin
Finding a sixpence, with transport beside his hope,
Runs to the tin-man and makes a caleidoscope!"

1819. THE HOBBY.

Another invention made its appearance in 1819: this was the
_velocipede_, or as it was then called "the hobby," the grandfather of
the bicycle and tricycle of our day. A tall