Science Siftings

New Zealand Tablet, 6 May 1915, Page 53

Science Siftings

By ‘ Volt.’

: _ Poland’s Salt Mines. .-, -, . ./v. I Wieliczka, eight miles from' Cracow, possesses the most wonderful salt mines in the world. They have been worked since the thirteenth century, and the workings now cover an area of twenty-four square miles. Many of the miners live permanently underground, where they have built a wonderful town, with streets, squares, public buildings, and tramways, which, together with the crystal vaults, sparkling aisles, and fairy palaces of the mines, have formed the background of numerous romances. The annual output of the Wieliczka mines is about 60,000 tons, f ' Heating Miles of Orchards. One of the greatest feats of artificial outdoor heating ever attempted was resorted to by some fruit growers in Colorado, to save a crop of fruit estimated at £600,000 in value. Thousands upon, thousands of smudge-pots were scattered through the orchards over twenty-seven miles of territory, and the raising of temperature that resulted effectually dispelled the unexpected frost. The smudge-pots used were of many different types, some burning oil and others coal. The temperature in the orchards was actually raised Bdeg and 9deg. over the entire twenty-seven miles, of territory, as many as 300,000 smudge-pots being used. * The Best Hour for Work. It is a curious fact in psychology that nobody can stay at the same mental and physical level for 24 hours together. In the morning you are more matter-of-fact, for instance, than later in the day. It is in the morning that the best brain work is done, too —brain work of the sort that requires industry and clear thinking. And it is about 11 in the morning that our body reaches its highest point of energy. In other words, you are stronger, though almost imperceptibly, at 11 in the morning than at 3in the afternoon. You reach that highest point twice in the day, for about 5 in the afternoon the muscular energy has risen again. But from 5 onward it declines steadily all through the evening, and on till between 2 and 3 a.m. Tall Men or Short? % Dr. M. S. Pembrey, lecturer on physiology at Guy’s Hospital, opened an interesting discussion recently at the Royal Sanitary Institute, London, on the-question of tall versus short men for the Army. A typical Scot (said Dr. Pembrey), would be considered a tall Welshman, in support of his contention that a man might be considered tall when his height was, four or five inches greater than that of the average of his countrymen. The difference in height between a tall and a. short man was due chiefly to the longer legs of the former, but height depended upon the correlated activity of certain glands which produced internal secretions and extremes. The essential organs, Dr. Pembrey added, were in the head and trunk, and these were often better developed in the short than in the tall man, the weight of the brain being relatively greater in the short man and the reaction time not so long. Tall men of full proportions, he contended, were heavy and often slow, and there were strong physiological reasons for the greater agility and activity of the small man, who did not suffer from the mechanical disadvantages of height and weight. The small man had a greater capacity for work, endurance, and stronger resistance to disease. Judging from the fighting capacity of tall and short races and from the fighting capacity of tall and short men of the same race, Dr, Pembrey summed up in favor of the short man, though he modified his remarks by warning his hearers to beware of the danger of rushing to extremes.