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Page:Popular Science Monthly Volume 34.djvu/588

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THE POPULAR SCIENCE MONTHLY.

British Gold-Mines.—The existence of gold in the British Islands, in quantities perhaps sufficient to pay for modest mining, seems to be established, thereby justifying Strabo's inclusion of the precious metals as among their products. In Wales, gold is found in Carmarthenshire and Merionethshire. At Gogafan, in the former county, are to be seen traces of extensive ancient (probably Roman) workings. At the Viga Cloga Mine, an average annual return of £2,500 was realized from 1860 to 1867, since when the yield has declined. In this mine the vein appears to have been more productive as the working was extended to a greater depth, contrary to what is generally believed about gold-mines. From the Cambrian Mine, 300 ounces, and from the Prince of Wales's Mine, from 300 to 400 ounces of gold have been extracted to the ton of ore. Gold-fields were worked in Ireland at the close of the last century, but operations were stopped in 1802 because the cost exceeded the profit. The attempt was renewed in 1840, but given up again on account of disputes. The principal mining sites were Ballin Valley, Ballintemple, and Killahurler. Gold-fields lie in Lanarkshire and Sutherlandshire in Scotland. They were worked with considerable profit in the days of the Jameses. The gold-field of southeast Sutherlandshire covers an area of thirty miles by twenty. The occurrence of gold in England is rather a matter of speculation; but it exists, and can be found and obtained. Mineral in north Cornwall has assayed eleven ounces to the ton. Mr. J. S. Farrer thinks that the reason no gold-mines are at present being worked in the United Kingdom may he "far more in the state of the law than in that of the ground."

 

Children's Punishments.—Something can be said in favor of most of the forms of correction—the rod, strap, tasks, confinement, restriction to plain food, and many others—which have been more or less employed in the school and the family. But there is one which on no account should be employed. Boxing or pulling the ears, or, indeed, striking any part of the head, is most injudicious. Not every form of corporal punishment is so objectionable, but in applying it judgment should be employed. Thus, if a chastisement suitable for a robust child is given to a nervous or feeble one, it will be doubly felt, and will be out of proportion to the offense. Moral means of correction may be the most suitable for sensitive children, and, in the case of school tasks, may possess a certain educational value. There is, however, an important objection to such as imply confinement indoors, especially in cases where the culprit is some poorly nourished youngster to whom fresh air is a luxury, or in any case where the punishment is frequently repeated.

 

Searching for the Canals of Mars.—In his report at the American Association on the aspect of Mars, as observed at the National Observatory, Washington, Prof. A. Hall said that while observing satellites in April, attempts were made on several nights to see the canals, but without success, and then it was determined to make the trial in twilight, when the observers could see more in detail on the surface of the planet. But nothing like the regular canals drawn by European observers could be seen, although the usual reddish and dark spots and markings were visible nearly every night.

 

Japanese Mirrors.—The peculiar property of the Japanese "magic mirrors," some of which reflect the figures carved or stamped on their hacks, was explained by Prof. Mendenhall, at the American Association. It has been known to the Japanese for a thousand years, but did not receive scientific attention till a few years ago, when a Frenchman studied out the reason of it. The mirrors are round metal disks with short handles covered with bamboo and curiously carved backs. The peculiar thing about them is that, when a ray of light is reflected from their surface upon a screen, instead of a mere blotch of light there appears a reflection of the figures upon the back of the metal. How this is accomplished Prof. Mendenhall explained on the principle of the divergence of rays of light from a convex surface. It has been discovered that the polished surfaces of some of the mirrors are slightly convex. In addition to this, the smooth surface is really irregular, though the irregularity can not be