Science Siftings

New Zealand Tablet, Volume XXXVII, Issue 12, 25 March 1909, Page 475

Science Sift ings

by • volt

The World's Highest Restaurant.

What is probably the highest restaurant in the wofld . has been- opened at the Eismeer station of the Jungfraurailway in Switzerland. It is ten thousand feet above the level of the sea, and close"- to tlie summit of the mountain. The food is not cooked by means of' ordinary fuel, but by electricity generated by the Lutschine waterfall, deep down in the valley below. Test for Children. Hand a person two objects which are of exactly the same weight, but of different dimensions, and the chances are ninety to one that he will pronounce, the smaller to be the heavier $f the two. The reason evidently "is because it 1 is natural, though erroneous, to suppose that the more compact a body is the heavier it is bound to be." JDr. Dernoor, a well-known Belgian physician, recently tested several children on this point. He gave them two .black bottles, each containing a similar quantity of heavy powder and one of which was much larger than the other, and of the 380 children whom he examined 370 said promptly the smaller bottle was the heavier. Only ten answered correctly, and Dr. Demoor soon found out that they were idiots. Professor E. Maparede applied the same test to a class of backward children in Geneva, and discovered that it was an admirable method for discovering the exact amount of intelligence possessed by each child. Tour of his pupils invariably picked out the bottle which was really the heavier, and these four were the dullest, and in all other respects the most unpromising in his entire class. A Tree Which Causes Headache. A curious member of the vegetable kingdom has been discovered in the Far East. It is a species of acacia, which grows to a height of about eight feet, and when full grown closes its leaves together in curls each day at sunset and curls its twigs in the form of a pigtail. After the tree has settled itself in this way for a night's sleep, like most sleepers it objects to being disturbed. If touched it will flutter as if agitated and impatient at the interruption of its slumbers. The often er the foliage is molested the more violent becomes the shaking of the branches, and at length the tree emits a nauseating odor, which, if inhaled for a few moments, will cause a violent headache. Our Day Growing Longer. The earth revolves on its axis once in twenty-four hours at present, yet millions of years ago it completed a revolution in a day of about five hours. It could revolve no faster than this and remain a single unbroken mass. Now, when our day was about five hours long, the moon, so astronomers tell us, was in contact with the surface of the earth. It had just broken away from the parent mass, but as our length of the terrestrial day increased so did the distance of the moon. Whenever the rotation time of a planet is shorter than the- period of the revolution of its satellite the effect of their mutual action is to accelerate the motion of the satellite and to compel it to move in an increased orbit — to amplify its distance. So now our day is" shorter than the month — the period of evolution — of the moon. Our satellite, therefore, is slowly receding from us, and it has been moving away for thousands of centuries. But the day of the earth is growing longer. So long as the terrestrial day ' is shorter \than the lunar month, the moon will continue to recede. from us. In time, so many - millions of years hence that they almost baffle computation, our day will be a month long and the moon will be lost in space.