SCIENCE SIFTINGS

New Zealand Tablet, Volume L, Issue 36, 13 September 1923, Page 54

SCIENCE SIFTINGS

By "VOLT** =

Why the Sea is Salt. Why should water in the sea be so salt? It is fed by rivers, which bring down a constant supply of fresh water. But is river water perfectly fresh? Try a little experiment. Fill one tumbler with water from which all the salts have been extracted, and another with river water. Now taste them. You will have no difficulty in distinguishing them. The flavor of salt in the river water will be quite noticeable, for all so-called "fresh” water is tinged with the salts in the earth, ... As streams and rivers run through the land, they melt away the soft pieces of the soil and carry them to the sea. In the soil are salts of various kinds, the commonest being sodium chloride, the chemical name for the salt which appears on our tables at meal-times. For ages past, salts have been washing down into the sea, where they have accumulated. The heat of the sun evaporates the water of the ocean, but this only serves to make the sea more salty, for the sun does not suck up any of the salts. Clock Without a Tick. A novel clock, new in design and conception, has been invented by an Edinburgh clockmaker. That this is a real scientific advance in the realm of horology is at once established by the fact that a paper was read, and the clock demonstrated before the Royal Society of Edinburgh, by Mr. Stuart, the inventor. The clock has a silent continuous motion (says the Scotsman). It has no “tick” or intermittent movement like an ordinary clock. The pendulum, which is driven by a gravity arm, is absolutely free, having no escapement to unlock, no mechanism to drive, nor any electrical contacts to make or break, thus realising what has been the clock makers’ dream for many a decade. Being driven by electricity it, of course, requires no winding. Two models were demonstrated to the Royal Society, one in the form of an accurate or precision regulator with a heavy pendulum, and the other in the form of a heavy powerful turret clock, such as is used in the huge dials on church tower or public clocks. Theformer, carefully checked over a long period by Paris observatory wireless time signals, has been regulated to within half a second per week. This is a marvellous result, when it is remembered that the timepiece as practically a rough model built for experimental purposes.' The clock is absolutely silent in operation, and its consumption of electrical energy is one-hundredth of a watt. In other words, the power used in an ordinary 60 watt electric light bulb is sufficient to drive six thousand such clocks. It is a weird sensation to witness the curious floating motion of the seconds hand as it traverses the dial without the familiar stopping jerk at each second. The other model exhibited, built on exactly the same principle, but designed to demonstrate the adaptability of the movement to the heaviest work, actually lifted half a hundredweight- at the end of a twelve-inch minute hand without in any way disturbing the time-keeping pendulum. This powerful movement or mechanism was contained in an 18-inch square. The Westminster clock, familiarly known as “Big Ben,” has a 7001 b pendulum, and could not equal this performance. One of the outstanding features of this patented principle is that accurate or precision time-keeping is now possible without the extremely fine workmanship which has hitherto been necessary. Further, the power available is unlimited, and in this respect, snow, frost, and wind, the present enemy of the maker of heavy clocks, and also the releasing of strike and chime movements, have now lost their terrors.