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dress; he is when prepared to descend, the oddest looking creature ever seen, he has an immense helmet of white metal over his head, and in front of his eyes are two large thick pieces of glass protected by bars of metal, this helmet is strongly strapped to his water proof dress, and he then presents a most laughable appearance; he is obliged to load himself with heavy weights before he gets into the water, otherwise his buoyancy would cause him to float on the surface, but thus loaded down he goes, and will pick up money or any small thing thrown down to him, walking about the bottom of the clear water as unconcerned as possible; a model of a ship containing a small charge of gunpowder is sunk some depth under the water, to which the diver attaches wires, communicating at a considerable distance with a Voltaic battery which when connected instantly explodes the powder and the vessel is shattered to pieces, thus illustrating Colonel Pasley's clever method of destroying the wreck of the Royal George at Spithead.
An illustration of the patented plan for preventing ships from sinking and for raising them when sunk without injury is also exhibited. The diving bell is made of cast iron, open at the bottom with seats all around, and is of the weight of three tons; the interior for the divers is lighted by openings in the crown of thick plate glass, which are firmly secured by brass frames screwed to the
bell: it is suspended by a massive chain to a large swing crane, with a powerful crab, the windlass of which grooved spirally and the chain passes four times over it into the well beneath, to which chain is suspended the compensation weights, and it is so accurately arranged, that the weight of the bell is at all depths counterpoised by the weight acting upon the spiral shaft; the bell is put into action several times a day, and visitors may safely descend a considerable depth into the tank, which with canals, holds nearly a thousand gallons of water, the whole of which if required, can be emptied in less than one minute. The diver's dress, helmet, air-tubes, &c., are patented articles, having been introduced by Mr. Deane. With the diving bell and the diver's dress, every thing almost can now be performed under water; the tops of piles can be sawn off, an eye bolt can be driven into a sunken vessel to make purchases fast to, in order that she may be hove up.
be hove up. Rocks can be blasted by the introduction into them, at any depth under water, of charges of powder, which can be exploded through water proof tubes, or by a galvanic battery by wires.
A gallery runs all round this hall, which is thickly studded with models and curiosities of all kinds. At each end of the gallery is placed large metallic circular reflectors, about twelve feet in diameter; they must be quite one hundred feet apart from each other,-and yet, although there is
a constant noise from the operations of the several working models, and of the number of persons who are talking, a person whispering to one, is distinctly heard by his friend at the opposite side in front of the other shield.
"The effect in looking down from this gallery upon the several things in constant motion, is quite enchanting, and we do not hesitate to say, that if we had seen nothing else in England besides the Adelaide Gallery and the Polytechnic Institution, we should have thought ourselves amply repaid for our voyage from India to England.
There can be nothing conceived more interesting to persons like ourselves, who having from an early age been taught to believe that next to our duty of thankfulness and praise to our God and Creator, that it is the duty of every man to do all that he can to make all mankind happy; we were early instructed that the man who devoted his energies to the works of science and of art deserved well of his fellow men. To us then brought up in India for scientific pursuits, and longing ardently to acquire practical information, connected with modern improvements, more particularly with naval architecture, steam engines, steam boats, and steam navigation, these two Galleries of practical science seemed to us to embrace all that we had come over to England to make ourselves acquainted with, and it was with gratitude to the original projectors of these insti
tutions that we gazed upon the soul exciting scene before us, we thought of the enchantments as related in the Arabian nights entertainments, and they faded away into nothingness compared with what we then saw.
Here within this limited space were miniature steam ships, with every possible variety of improved machinery, gliding upon the water ; here were exhibited all and every description of paddle wheels for propelling them through the water. There was a ship upon the stays ready to be launched upon the removal of the dog shores ; here was every possible variety of lock gates for entrances to wet docks, calculated to open with facility and to resist the pressure of a great weight of water when the ship was in dock; here you could learn how safely to descend into the sea with different contrivances and here you were taught how you might best ascend into the air in a Balloon. Here the scientific man for hours and days may acquire valuable information and here the man in quest of pleasure and amusement may day after day gaze upon pleasing inventions and beautiful models of a light nature to please the eye whilst his ear would be charmed with good music.
It is not our intention to describe all we saw at the Polytechnic, or to follow any particular rule or order with them, but we must point out a few of those things which most delighted us. We should speak first of models; steam boats, life boats, &c.
invented by Captain George Smith, R. N. a temporary rudder fitted with chain rings, a lower mast fitted with iron fishes to preserve it if wounded or injured, paddle wheels fitted with grooved and cogged wheels for the application of manual labour at the capstan and winches in case of accident to the steam engine or to be used before the steam can be got up, an alarum to be used on board steam vessels in a fog, the gong or bell to be constantly kept striking by the machinery, a life boat formed of the upper section of the paddle box of steam vessels, the ends are made with two air tight cases or tanks, and the model is intended to shew the practicability of every steam vessel carrying two large boats for the purpose of saving the lives of the passengers and crew in the event of the vessel being burnt, wrecked, or sunk by coming in collision with other vessels. The model is fitted to shew an easy method of getting the boats into the water when required, this plan has been adopted and fitted to Her Majesty's steam vessels Carron and Firefly and to the Pacific company's vessels, Chili and Peru, and ordered for those of the Royal Mail company and of the Niger expedition; there are also plans of his for propelling steam vessels by propellers in the shape of feathered wheels astern the vessels, instead of having paddle wheels at the side; all these things look very pretty in models, and many persons think if they perform correctly