Upon examining the edge of the circular medallions, Mr. Brockedon discovered in all of them, except the blanks, a small hole almost concealed by the milling. This led Mr. Brockedon to examine the receptacle for the medallion in the drawer, and he observed the edge of a pin flush with the edge of the receptacle, whence the pin was protruded by the machine into the holes in the medallion, the depth of the hole regulating the answer. In order to prove this, Mr. B. cut a slip from a cedar pencil small enough to enter easily the holes in the medallion, if he found them to be of different depths. As the blank medallions had no hole, and produced only a shake of the magician’s head, Mr. B. took a medallion with a question, and having plugged the hole with a bit of cedar, he cut it flush, and having placed it in the receptacle, the conjuror shook his head, and thus bore testimony to the truth of Mr. Brockedon’s discovery. M. Maillardet has constructed various other automata, representing insects and other animals. One of these was a spider entirely made of steel, which exhibited all the movements of the animal. It ran on the surface of a table during three minutes, and to prevent it from running off, its course always tended towards the centre of the table. He constructed likewise a caterpillar, a lizard, a mouse, and a serpent. The serpent crawls about in every direction, opens its mouth, hisses, and darts out its tongue. Ingenious and beautiful as all these pieces of mechanism are, and surprising as their effects appear even to scientific spectators, the principal object of their inventors was to astonish and amuse the public. We should form an erroneous judgment, however, if we suppose that this was the only result of the ingenuity which they displayed. The passion for automatic exhibitions, which characterized the 18th century, gave rise to the most ingenious mechanical devices, and introduced among the higher orders of artists habits of nice and accurate execution in the formation of the most delicate pieces of machinery. The same combination of the mechanical powers which made the spider crawl, or which waved the tiny rod of the magician, contributed in future years to purposes of higher import. Those wheels and pinions, which almost eluded our senses by their minuteness, re-appeared in the stupendous mechanism of our spinning-machines and our steam-engines. The elements of the tumbling-puppet were revived in the chronometer, which now conducts our navy through the ocean; and the shapeless wheel which directed the hand of the drawing automaton has served, in the present age, to guide the movements of the tambouring engine. Those mechanical wonders, which in one century enriched only the conjuror who used them, contributed in another to augment the wealth of the nation; and those automatic toys, which once amused the vulgar, are now employed in extending the power and promoting the civilization of our species.