SCIENCE SIFTINGS

New Zealand Tablet, 13 March 1919, Page 46

SCIENCE SIFTINGS

By "Volt."

* ; Forty-Two Storeys High. The highest building in America west of the Mississippi is in Seattle, Washington. The tower rises 450 feet above street level. The building covers a plot that is 108 feet by 120 feet. The main structure is twenty-one storeys high, and to this the tower adds twelve storeys. In addition to this there are two storeys below street, level. The height to the lantern at the top of the tower is equivalent to forty-two storeys. The foundation rests on 1276 concrete piles driven to a depth of 50 feet below the surface. In building the foundation 4000 barrels of cement and more than 1000 tons of steel were used. On the foundation piles a total weight of 76,560 gross tons is carried, the steel for the superstructure alone weighing 4732 gross tons. Guns at Sea. Naturally, being continually on the move, a warship is a much less satisfactory gun platform than the solid earth. Even in the calmest sea vessels constantly roll from side to side. Theoretically, the best time to fire is at the moment between the rolls, when the deck is perfectly level. It is practically impossible, however, to fire exactly at that moment. No matter how careful the gunner may he fires his gun just before or just after the proper instant. The rule in the American Navy is to "wait for the downward roll"—that is, fire at the moment the ship is about to move down through the motion of the waves. The maxim in the British Navy is exactly the reverse; that is, "wait for the upward roll," a rule that has been observed from the very earliest days of fighting by the gunners in British ships. The Revolving Earth. Take a good-sized bowl, fill it nearly full of water, and place it upon the floor of a room which is - not exposed to shaking or jarring from the street. Sprinkle over the surface of the water a coating of lycopodium powder, which can be obtained at almost any chemist's. Then upon the surface of this coating of powder make with powdered charcoal a straight black line, say an inch or two in length. Having made this little mark with the charcoal powder on the surface of the contents of the bowl, lay down on the floor close to the bowl a stick or some other straight object, so that it will be exactly parallel with the mark. If the line happens to be parallel with a crack in the floor or with any stationary object in the room, this will serve as well. Leave the bowl undisturbed for a few hours, and then observe the position of the black mark with reference to the object with which it was parallel. It will be found to have moved in the direction opposite to that of the earth on its axis. The earth in simply revolving, has carried the water and everything else in the bowl round with it, but the powder on the surface has been left behind a little. The line will always be found to have moved from east to west, which is perfectly good proof that everything else has moved the other way.