Dr. Paris has already shown, in a charming little book treating
scientifically of children’s toys, how easy even “philosophy in sport
can be made science in earnest.” An earlier genius cut out the whole
alphabet into the figures of uncouth animals, and enclosed them in a
toybox representing Noah’s Ark, for the purpose of teaching children
their letters. Europe, Asia, Africa, and America have been decimated;
“yea, the great globe itself,” has been parcelled into little wooden
sections, that their readjustment into a continuous map might teach the
infant conqueror of the world the relative positions of distant
countries. Archimedes might have discovered the principle of the lever
and the fundamental principles of gravity upon a rocking-horse. In like
manner he might have ascertained the laws of hydrostatics, by observing
the impetus of many natural and artificial fountains, which must
occasionally have come beneath his eye. So also the principles of
acoustics might even now be taught by the aid of a penny whistle, and
there is no knowing how much children’s nursery games may yet be
rendered subservient to the advancement of science. The famous Dr.
Cornelius Scriblerus had excellent notions on these subjects. He
determined that his son Martinus should be the most learned and
universally well-informed man of his age, and had recourse to all sorts
of devices in order to inspire him even unthinkingly with knowledge. He
determined that everything should contribute to the improvement of his
mind,—even his very dress. He therefore, his biographer informs us,
invented for him a geographical suit of clothes, which might give him
some hints of that science, and also of the commerce of different
nations. His son’s disposition to mathematics—for he was a remarkable
child—was discovered very early by his drawing parallel lines on his
bread and butter, and intersecting them at equal angles, so as to form
the whole superficies into squares. His father also wisely resolved that
he should acquire the learned languages, especially Greek,—and
remarking, curiously enough, that young Martinus Scriblerus was
remarkably fond of gingerbread, the happy idea came into his parental
head that his pieces of gingerbread should be stamped with the letters
of the Greek alphabet; and such was the child’s avidity for knowledge,
that the very first day he eat down to _iota_.
When Sir Isaac Newton changed his residence and went to live in
Leicester Place, his next door neighbour was a widow lady, who was much
puzzled by the little she observed of the habits of the philosopher. One
of the Fellows of the Royal Society, called upon her one day, when among
other domestic news, she mentioned that some one had come to reside in
the adjoining house, who she felt certain was a poor mad gentleman. “And
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
sightseers. 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 staircase, 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, are constantly used in repairing the
bottom of docks, landing-piers, and in the construction of breakwater
works, such as those which are at present being raised at Dover Harbour.
Among other remarkable objects in the museum of natural history we
recognised, swimming upon his shingly bed under a glass case, our old
friend the Gymnotus Electricus, or Electrical Eel. Truly, he is a
marvellous fish. The power which animals of every description possess in
adapting themselves to external and adventitious circumstances, is here
marvellously illustrated, for, notwithstanding this creature is
surrounded by the greatest possible amount of artificial circumstances,
inasmuch as instead of sporting in his own pellucid and sparkling waters
of the River Amazon, he is here confined in a glass prison, in water
artificially heated; instead of his natural food, he is here supplied
with fish not indigenous to his native country, and denied access to
fresh air, with sunlight sparkling upon the surface of the waves—he is
here surrounded by an impure and obscure atmosphere, with crowds of
people constantly moving to and fro and gazing upon him;—yet,
notwithstanding all these disadvantageous circumstances, he has
continued to thrive; nay, since we saw him, ten years ago, he has
increased in size and is apparently very healthy, notwithstanding that
he is obviously quite blind.
This specimen of the Gymnotus Electricus was caught in the River Amazon,
and was brought over to this country by Mr. Potter, where it arrived on
the 12th of August, 1838, when he displayed it to the proprietors of the
Adelaide Gallery. In the first instance, there was some difficulty in
keeping him alive, for, whether from sickness, or sulkiness, he refused
food of every description, and is said to have eaten nothing from the
day he was taken in March, 1838, to the 19th of the following October.
He was confided upon his arrival to the care of Mr. Bradley, who placed
him in an apartment the temperature of which could be maintained at
about seventy-five degrees Fahrenheit, and acting upon the suggestions
of Baron Humboldt, he endeavoured to feed him with bits of boiled meat,
worms, frogs, fish, and bread, which were all tried in succession. But
the animal would not touch these. The plan adopted by the London
fishmongers for fattening the common Eel was then had recourse to;—a
quantity of bullock’s blood was put into the water, care being taken
that it should be changed daily, and this was attended with some
beneficial effects, as the animal gradually improved in health. In the
month of October it occurred to Mr. Bradley to tempt him with some small
fish, and the first gudgeon thrown into the water he darted at and
swallowed with avidity. From that period the same diet has been
continued, and he is now fed three times a day, and upon each occasion
is given two or three carp, or perch, or gudgeon, each weighing from two
to three ounces. In watching his movements we observed, that in swimming
about he seems to delight in rubbing himself against the gravel which
forms the bed above which he floats, and the water immediately becomes
clouded with the mucus from which he thus relieves the surface of his
body.
When this species of fish was first discovered, marvellous accounts
respecting them were transmitted to the Royal Society: it was even said
that in the River Surinam, in the western province of Guiana, some
existed twenty feet long. The present specimen is forty inches in
length; and measures eighteen inches round the body; and his physiognomy
justifies the description given by one of the early narrators, who
remarked, that the Gymnotus “resembles one of our common eels, except
that its head is flat, and its mouth wide, like that of a cat-fish,
without teeth.” It is certainly ugly enough. On its first arrival in
England, the proprietors offered Professor Faraday (to whom this country
may possibly discover, within the next five hundred years, that it owes
something) the privilege of experimenting upon him for scientific
purposes, and the result of a great number of experiments, ingeniously
devised, and executed with great nicety, clearly proved the identity
between the electricity of the fish and the common electricity. The
shock, the circuit, the spark, were distinctly obtained; the
galvanometer was sensibly affected; chemical decompositions were
obtained; an annealed steel needle became magnetic, and the direction of
its polarity indicated a current from the anterior to the posterior
parts of the fish, through the conductors used. The force with which the
electric discharge is made is also very considerable, for this
philosopher tells us we may conclude that a single medium discharge of
the fish is at least equal to the electricity of a Leyden Battery of
fifteen jars, containing three thousand five hundred square inches of
glass, coated upon both sides, charged to its highest degree. But great
as is the force of a single discharge, the Gymnotus will sometimes give
a double, and even a triple shock, with scarcely any interval. Nor is
this all. The instinctive action it has recourse to in order to augment
the force of the shock, is very remarkable.
The Professor one day dropped a live fish, five inches long, into the
tub; upon which the Gymnotus turned round in such a manner as to form a
coil enclosing the fish, the latter representing a diameter across it,
and the fish was struck motionless, as if lightning had passed through
the water. The Gymnotus then made a turn to look for his prey, which
having found, he bolted it, and then went about seeking for more. A
second smaller fish was then given him, which being hurt, showed little
signs of life; and this he swallowed apparently without “shocking it.”
We are informed by Dr. Williamson, in a paper he communicated some years
ago to the Royal Society, that a fish already struck motionless gave
signs of returning animation, which the Gymnotus observing, he instantly
discharged another shock, which killed it. Another curious circumstance
was observed by Professor Faraday,—the Gymnotus appeared conscious of
the difference of giving a shock to an animate and an inanimate body,
and would not be provoked to discharge its powers upon the latter. When
tormented by a glass rod, the creature in the first instance threw out a
shock, but as if he perceived his mistake, he could not be stimulated
afterwards to repeat it, although the moment the Professor touched him
with his hands, he discharged shock after shock. He refused, in like
manner, to gratify the curiosity of the philosophers, when they touched
him with metallic conductors, which he permitted them to do with
indifference. It is worthy of observation, that this is the only
specimen of the Gymnotus Electricus ever brought over alive into this
country. The great secret of preserving his life would appear to consist
in keeping the water at an even temperature—summer and winter—of
seventy-five degrees of Fahrenheit. After having been subjected to a
great variety of experiments, the creature is now permitted to enjoy the
remainder of its days in honorable peace, and the only occasion upon
which he is now disturbed, is when it is found necessary to take him out
of his shallow reservoir to have it cleaned, when he discharges angrily
enough shock after shock, which the attendants describe to be very
smart, even though he be held in several thick and well wetted cloths,
for they do not at all relish the job.
The Gymnotus Electricus is not the only animal endowed with this very
singular power; there are other fish, especially the Torpedo and
Silurus, which are equally remarkable, and equally well known. The
peculiar structure which enters into the formation of their electrical
organs, was first examined by the eminent anatomist John Hunter, in the
Torpedo; and, very recently, Rudolphi has described their structure with
great exactness in the Gymnotus Electricus.
Without entering into minute details, the peculiarity of the organic
apparatus of the Electrical Eel seems to consist in this, that it is
composed of numerous _laminæ_ or thin tendinous partitions, between
which exists an infinite number of small cells filled with a thickish
gelatinous fluid. These strata and cells are supplied with nerves of
unusual size, and the intensity of the electrical power is presumed to
depend on the amount of nervous energy accumulated in these cells,
whence it can be voluntarily discharged just as a muscle may be
voluntarily contracted. Furthermore, there are, it would appear, good
reasons to believe that nervous power (in whatever it may consist) and
electricity are identical. The progress of Science has already shown the
identity between heat, electricity, and magnetism;—that heat may be
concentrated into electricity, and this electricity reconverted into
heat; that electric force may be converted into magnetic force, and
Professor Faraday himself discovered how, by reacting back again, the
magnetic force can be reconverted into the electric force, and _vice
versâ_; and should the identity between electricity and nervous power be
as clearly established, one of the most important and interesting
problems in Physiology will be solved.
Every new discovery in Science, and all improvements in Industrial Art,
the principles of which are capable of being rendered in the least
degree interesting, are in this Exhibition forthwith popularised, and
become, as it were, public property. Every individual of the great
public can at the very small cost of one shilling, claim his or her
share in the property thus attractively collected, and a small amount of
previous knowledge or natural intelligence will put the visitor in
actual possession of treasures which previously “he wot not of,” in so
amusing a manner that they will be beguiled rather than bored into his
mind.