When Sir Isaac Newton changed his residence and went to live in Leicester-place, his next door neighbor 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 favorite diversion, for it is a fine day; do come and look at him.” The gentleman smiled; and they went up-stairs, when after looking through the stair-case 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 marvelous 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-plow; there, a Manchester or Birmingham manufacturer looking into a curious and complicated weaving machine; here, we noticed a group of ladies admiring specimens of [pg 598] 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 a 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 skeptical 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 Harbor.
Among other remarkable objects in the museum of natural history we recognized, swimming upon his shingly bed under a glass case, our old friend the Gymnotus Electricus, or Electrical Eel. Truly, he is a marvelous fish. The power which animals of every description possess in adapting themselves to external and adventitious circumstances, is here marvelously 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 endeavored 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 [pg 599] 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.