An anecdote will suffice to illustrate the advantages of the electric over the visual variety of telegraph—the one being only workable in certain states of the weather; the other available in all states. Upon one occasion, when the British army were fighting in Spain, intelligence was every day feverishly expected from Wellington through the medium of the semaphore at the Admiralty. Long delayed, it came at last, and was apparently of a fearful character. It ran thus: "Wellington defeated." Parliament and the people were stunned for a time, and rumours flew about like wildfire to this effect. It turned out, however, that just as the word "defeated" was deciphered, a fog intervened, and cut off the rest of the communication. When the dark pall disappeared, the bright sky disclosed to a jubilant people, not "Wellington defeated," but "Wellington defeated—the French!"
A WRENCH TO OLD ST. PAUL'S.
When, after much mean and yet costly endeavour to patch up the cathedral of St. Paul's, after the great fire, Sir Christopher Wren at last had his advice accepted, to rebuild the whole structure, the demolition of the old fabric gave ample play to his scientific knowledge and engineering skill. One of his exploits, perhaps now more remarkable because at the time it was at once rare and bold, has thus been described:—"In order that the rubbish and old materials might not hinder the setting out of the foundations, for the purpose of proceeding with the works, Sir Christopher constructed scaffolds high enough to extend his lines over the heaps that were in the way; and thereby caused perpendiculars to be fixed upon the points below for his various walls and piers, from lines drawn carefully upon the level plan of the scaffold. Thus he proceeded, gaining every day more and more room, till he came to the middle tower that formerly carried the lofty spire. The ruins of this tower being nearly two hundred feet high, the labourers were afraid to work above, which induced him to facilitate the labour by the use of gunpowder. To perform this work, he caused a hole to be dug, of about four feet wide, by the side of the north-west pier of the tower, in which was perforated a hole two feet square, reaching to the centre of the pier. In this he placed a small deal box containing eighteen pounds of gunpowder. To this box he affixed a hollow cane, which contained a quick match, reaching to the surface of the ground above; and along the ground a train of powder was laid, with a match. The mine was then closed up, and exploded, while the philosophical architect waited with confidence the result of his experiment. This small quantity of powder not only lifted up the whole angle of the tower, with two great arches that rested upon it, but also two adjoining arches of the aisle, and the masonry above them. This it appeared to do in a slow but efficient manner, cracking the walls to the top, lifting visibly the whole weight about nine inches, which suddenly dropping, made a great heap of ruins in the place, without scattering or accident. It was half a minute before the heap already fallen opened in two or three places, and emitted smoke. By this successful experiment, the force of gunpowder may be ascertained; eighteen pounds only of which lifted up a weight of more than three thousand tons, and saved the work of a thousand labourers. The fall of so great a weight from a height of two hundred feet gave such a concussion to the ground, that the inhabitants round about took it for the shock of an earthquake."
SNOW SPECTACLES.
Ellis, in his Voyage to Hudson's Bay, written in the middle of last century, says of the Esquimaux:—"Their snow eyes, as they very properly call them, are a proof of their sagacity. They are little pieces of wood or ivory, properly formed to cover the organs of vision, and tied on behind the head. They have two slits, of the exact length of the eyes, but very narrow; and they see through them very distinctly, and without the least inconvenience. This invention preserves them from snow-blindness, a very dangerous and powerful malady, caused by the action of the light strongly reflected from the snow, especially in the spring, when the sun is considerably elevated above the horizon. The use of these eyes considerably strengthens the sight, and the Esquimaux are so accustomed to them, that when they have a mind to view distant objects, they commonly use them instead of spy-glasses."
A SELF-TAUGHT MECHANIST.
The following description is given of an ingenious and singular piece of mechanism—constructed by a boy of the name of John Young, who in 1819 resided at Newton-on-Ayr—which attracted much notice among the scientific of the day:—"A box, about three feet long by two broad, and six or eight inches deep, had a frame and paper covering erected on it, in the form of a house. On the upper part of the box are a number of wooden figures, about two or three inches high, representing people employed in those trades and sciences with which the boy is familiar. The whole are put in motion at the same time by machinery within the box, acted upon by a handle like that of a hand-organ. A weaver upon his loom, with a fly-shuttle, uses his hands and feet, and keeps his eye upon the shuttle, as it passes across the web. A soldier, sitting with a sailor at a public-house table, fills a glass, drinks it off, then knocks upon the table, upon which an old woman opens a door, makes her appearance, and they retire. Two shoemakers upon their stools are seen, the one beating leather, and the other stitching a shoe. A cloth-dresser, a stone-cutter, a cooper, a tailor, a woman churning, and one teasing wool, are all at work. There is also a carpenter sawing a piece of wood, and two blacksmiths beating a piece of iron, the one using a sledge, and the other a small hammer; a boy turning a grindstone, while a man grinds an instrument upon it; and a barber shaving a man, whom he holds fast by the nose with one hand. The boy was only about seventeen years of age when he completed this curious work, and since the bent of his mind could be first marked, his only amusement was that of working with a knife, and making little mechanical figures. This is the more extraordinary, as he had no opportunity whatever of seeing any person employed in a similar way. He was bred a weaver with his father, and since he could be employed at the trade, has had no time for his favourite study, except after the work ceased, or during the intervals; and the only tool he ever had to assist him was a pocket-knife. In his earlier years he produced several curiosities on a smaller scale; but the one now described is his greatest work, to which he devoted all his spare time during two years."