why so?" asked her friend. "Because," said
she, "he diverts himself in the oddest way
imaginable. Every morning when the sun
shines so brightly that we are obliged to
draw down the window-blinds, he takes his
seat on a little stool before a tub of
soap-suds, and occupies himself for hours
blowing soap-bubbles through a common
clay-pipe, which he intently watches floating
about until they burst. He is doubtless,"
she added, "now at his favourite diversion, for
it is a fine day; do come and look at him."
The gentleman smiled; and they went
upstairs, when after looking through the staircase
window into the adjoining court-yard, he
turned round and said, "My dear lady, the
person whom you suppose to be a poor
lunatic, is no other than the great Sir Isaac
Newton studying the refraction of light upon
thin plates, a phenomenon which is beautifully
exhibited upon the surface of a common
soap-bubble."

The principle, illustrated by the examples
we have given, has been efficiently followed
by the Directors of the Royal Polytechnic
Institution in Regent Street, London. Even
the simplest models and objects they exhibit
in their extensive halls and galleries, expound
—like Sir Isaac Newton's soap-bubble—some
important principle of Science or Art.

On entering the Hall of Manufactures (as
we did the other day) it was impossible not to
be impressed with the conviction that we are
in an utilitarian age in which the science of
Mechanics advances with marvellous rapidity.
Here we observed steam-engines, hand-looms,
and machines in active operation, surrounding
us with that peculiar din which makes the air

"Murmur, as with, the sound of summer-flies."

Passing into the "Gallery in the Great
Hall," we did not fail to derive a momentary
amusement, from observing the very different
objects which seemed most to excite the
attention and interest of the different sight-
seers. Here, stood obviously a country farmer
examining the model of a steam-plough;
there, a Manchester or Birmingham
manufacturer looking into a curious and
complicated weaving machine; here, we noticed
a group of ladies admiring specimens of
elaborate carving in ivory, and personal
ornaments esteemed highly fashionable at the
antipodes; and there, the smiling faces of
youth watching with eager eyes the little
boats and steamers paddling along the Water
Reservoir in the central counter. But we
had scarcely looked around us, when a bell
rang to announce a lecture on Voltaic
Electricity by Dr. Bachhoffner; and moving
with the stream of people up a short stair-
case, we soon found ourselves in a very
commodious and well arranged theatre. There
are many universities and public institutions
that have not better lecture rooms than this
theatre in the Royal Polytechnic Institution.
The lecture was elementary and exceedingly
instructive, pointing out and showing by
experiments, the identity between Magnetism
and Electricity—light and heat: but
notwithstanding the extreme perspicuity of the
Professor, it was our fate to sit next two old
ladies who seemed to be very incredulous
about the whole business.

"If heat and light are the same thing,"
asked one, "why don't a flame come out at
the spout of a boiling tea-kettle?"

"The steam," answered the other, may
account for that."

"Hush!" cried somebody behind them;
and the ladies were silent: but it was plain
they thought Voltaic Electricity had something
to do with conjuring, and that the lecturer
might be a professor of Magic. The lecture
over, we returned to the Gallery, where we
found the Diving Bell just about to be put
in operation. It is made of cast iron, and
weighs three tons; the interior being
provided with seats, and lighted by
openings in the crown, upon which a plate
of thick glass is secured. The weighty
instrument suspended by a massive chain to
a large swing crane, was soon in motion, when
we observed our sceptical lady-friends join a
party and enter, in order, we presume, to
make themselves more sure of the truth of
the diving-bell than they could do of the
identity between light and heat. The Bell
was soon swung round and lowered into a
tank, which holds nearly ten thousand gallons
of water; but we confess our fears for the
safety of its inmates were greatly appeased,
when we learned that the whole of this
reservoir of water could be emptied in less
than one minute. Slowly and steadily was
the Bell drawn up again, and we had the
satisfaction of seeing the enterprising ladies and
their companions alight on terra firma, nothing
injured excepting that they were greatly flushed
in the face. A man, clad in a water-tight
dress and surmounted with a diving helmet,
next performed a variety of sub-aqueous feats;
much to the amusement and astonishment of
the younger part of the audience, one of
whom shouted as he came up above the
surface of the water, "Oh! Ma'a! Don't he
look like an Ogre!" and certainly the shining
brass helmet and staring large plate-glass
eyes fairly warranted such a suggestion.
The principles of the Diving Bell and of
the Diving Helmet, are too well known to
require explanation; but the practical utility
of these machines is daily proved. Even
while we now write, it has been ascertained
that the foundations of Blackfriars Bridge are
giving way. The bed of the river, owing to
the constant ebb and flow of its waters, has
sunk some six or seven feet below its level,
since the bridge was built, thus undermining
its foundation; and this effect, it is presumed,
has been greatly augmented by the removal
of the old London Bridge, the works
surrounding which operated as a dam in checking
the force of the current. These machines, also