Science Siftings

New Zealand Tablet, 13 June 1912, Page 59

Science Siftings

By 'Volt.'-

Icebergs.

No two icebergs appear to be exactly alike in size and shape. Some look for all the world like Arabs' tents as they glide along, and others like cliffs, castles, cathedrals, yachts, and occasionally they resemble some well-known animal. Some of the pinnacles of a large berg rise nearly 1000 feet above the water, while the base may occupy an area of ten or twelve acres. Seen through a powerful glass, one may detect waterfalls upon these islands of ice and all kinds of Arctic birds, and perhaps a few seals.

Priest Invents Alarm.

A combined burglar and fire alarm was exhibited in Baltimore recently, by its inventor, Rev. Emidio Orlandi, of Rome, Italy. Father Orlandi claims that his machine when set in a room where a safe or other depository for valuables is kept will not only detect the thief and sound an alarm, but will photograph the intruder in action. As soon as the thief attempts to tamper with a safe the mechanism, which resembles a clock, is set in motion, a flashlight is set off and the film exposed. In case of fire the apparatus sounds a bell or it can be connected with fire protection companies' offices and notification of a blaze given.

Green Wall Paper.

There are still people who refuse to sleep in a room that has a green paper on the walls. They know that not so many years ago it was discovered that a great many people were poisoned by sleeping in rooms that had green paper when they did not leave the windows open for ventilation at night, as they should. Green dye was very hard to find, and most of the wall paper makers used salts of arsenic, which is a deadly poison. But one day there was born in England a very inquisitive boy named Perkins, who wanted to investigate everything when he grew up. As he got older he started to make experiments with things that no one else cared to bother with, and, among other things, he found that beautiful dyes of all colors could be made from common coal tar. So now arsenic is not used in wall papers or in any other dyes for domestic use, as the coal tar dyes are much cheaper and better. But there are still some people who do not know this, and that is why they do not like sleeping rooms with green paper on the walls.

An Electric Lift-Bridge.

The new bridge over the Missouri River, just being completed at Kansas City, is to have a draw that is lifted bodily into the air, to let vessels pass, instead of tilting up at one end like the rolling-lift bridges or swinging outward on a pivot. The new bridge will be remarkable not only as for its size (having the longest riveted span yet built), but even more so for the quickness with which it can be placed in position to allow vessels to pass. The upper deck is wide enough for two , street cars, two teams, and two walks abreast each other, and is stationary. Below it is a double-tracked railroad deck which can be raised by means of electric motors so as to clear the river steamers. This movable deck weighs 1,500,000 pounds, but the counterweighing J and the lifting apparatus have been so cleverly designed by the engineers that it will take only 50 seconds to raise or lower this deck. Even at high water, the bridge will give a clearance height of 55 feet when the lower deck is raised, and the delaying of trains by their being bridged will be reduced to an almost negligible amount.