Science Siftings

New Zealand Tablet, Volume XXXIV, Issue 13, 29 March 1906, Page 29

Science Siftings

By 'Volt*

Messrs. Harland and WolH announce that the White Star liner ' Adriatic,' which they are building, will be the largest vessel in. the world. She will have a displacement of 25,000 tons, will be 7lO£ feet long, 75 ieet broad, and 50 feet deep. Hus"banding Coal Supplies. A striking suggestion for husbanding Great Britain's fuel resources was made Ithe) other day by Mr. Geo. D. Bedley, in a lecture at Glasgow. He snowed that general use of the gas engine and the steam turbine for power would reduce the coal consumption to 2.4 tons per indicated horse-power per annum, equivalent to a total yearly saving of 28,000,000 tons, which, at 7s per ton, would represent a value (i £9,800,000. As the cost of the change would not exceed £50,000,000, the saving in coal would return 19.6 per cent. If this power were to be delivered as 'electricity, the cost of change would be £60,000,000, but the gain in efficiency and convenience would in many cases equal the saving in coal. The Food of the Future. E.ven if the world should not be fed on chemical products, there is every reason to believe that the'food of a few generations hence will differ greatly from that of to-day. As population grows we shall doubtless tend to become vegetarians, for it has been found that 12 acres of land are necessary to sustain one man on fresh meat,, 'b|ut that 42 people can be fed from the same area devote-d to wheat. One prophecy is that the time is approaching when the human race will live chiefly on the fruit of trees. Humboldt estimated that an acre banana plantation will feed 25 human beings, while a potaitu field af the same size wouid support only two,<, land a wheat farm only one ; and be further discovered that a grove of full-grown chestnut trees •will yield six times as much nourishment per acre as any cereal crop. With the reclaiming of deseit areas by irrigation, the planting of "date palms, bananas, and other fruitJ trees will result in a vast new supply til palatable and nutritious food. Maritime Engineering Enterprise. Dredging is one of the most characteristic operations of modern maritime engineering enterprise, the inevitable outcome of recent developments in the science of shipbuilding. So recently as 18dO, the deepest vessel in the Atlantic did'not exceed 24 feet, while in the P. and O. service the maximum was 20ft, and in the Cape service only 14 feet. The most modern vessels have load-line draughts considerably in excess of 30 feet, and in the case of such mammoths as the ' Celtic,' the ' Cediic,' and the ' Baltic,' the full depth cf draught attains to no less than 37 feet. Liverpool (says a writer in a scientific monthly) deepened her bar channel by 16 feet wifhin tKe last fifteen years. Antwerp has removed from the bed of the Scheldt extensive shoals which limited her accessibility and hampeibd her trade, while New York hopes in a few years' time to acquire a navigable entrance affording a minimum draught o\ 40 feet. Ten powerful dredges arc continuously at work' on the Mississippi, half a dozen on the St. Lawrence, and twice as many on the Maas. The Seine, the Volga, the Danube, the Garonne, the Clyde, the Tyne, the Tees, and a score of other rivers are the loci of extensive dredging operations. Phenomena of Sleep. Shakespeare called sleep the ape of death. That is a striking name for a striking thing. Sleep is a wonderland. There is no torture equal to that which the deprivation of sleep entails. The most ingenious of torturers place the; deprivation of sleep at the head of their torture list. Sleep is a state of rest. The heart rests in sleep. The heart is a rhythmetic muscle, not one that never reposes, but one that works at short shifts,* like &| puddler, a moment on, a moment off. When we sleep, the heart's shifts of rest are redoubled. It works then, one on, two ofi, getting, dndeed, pretty nearly as much repose as we do. The brain in sleep becomes pale,, and sinks below the level of the skull. When! we are awake the brain is high and full and ruddy. Not only the brain and heart,, but even the tear glands rest in sleep. That is why, when we awake, wo always rub our eyes. The rubbing is an instinctive action that stimulates the stagnant tear glands and causes them to moisten properly our eyes, all dried from in action.