SCIENCE NOTES

New Zealand Times, Volume LXXV, Issue 5134, 28 November 1903, Page 10

SCIENCE NOTES

OFFENSIVE AND DEFENSIVE POWERS OF NATURAL MAN. That man apart from his special intelligence, ia one of the weakest of all animals for aggression is no doubt correct, ho being about the only one of his size who has been left by nature wholly unarmed. Ho has neither claw nor horn nor jaw capable of rendering, or hoof or paw that of itself or untrained can strike a deadly blow, the natural man being, with few exceptions, entirely unaware of the power latent in his own fist, and striking always with tho hand unclosed. But for defence man in his savage state is probably as well provided its any, except tho most formidable beasts of prey. He certainly could not contend with tiger, lion, panther, or elephant, but he could run away, and as he is among THE SWIFTEST OF ANIMALS, would probably escape. He is, however, possessed of a faculty evolved _in no other animal of equal speed, of climbing a tree. In a stale of civilisation tins dexterity is largely lost, but in the' savago state it remains almost unimpaired. A schoolboy can climb in a way, but a savage will go straight up a smooth polo, using his feet as if they wero a second pair of hands, and crossing from tree to tree with marvellous facility. The civilised man cannot do it because bo has lost much of tho use of hia feet, partly front shoes, but more from reiianco on his hands and intelligence for everything. Not only that, but he has likewise lost the power of looking down w’ith unconcern from a height, a power belonging to all savages, and capable of being re-established by training, as ill the case of bridge carpcjjtei-s and steeple-jacks. A wild beast would not have an easy prey of an “animal” who could run a short distance as fast as an ordinary horse, climb like a inonkey, and swim as no other land animal can. A VESSEL WITH FINS. Tho method of bringing a- vessel to a stop by tho use of brakes >in the shape of fins fixed along the side of tho hull bejlqw water-line, has recently received tho indorsement of an agent, of tho Canadian Government appointed to examine into the merits of tlie scheme. The Canadian Government turned over tho steamer Eureka to tho inventor of this system, Louis Li) post p. apd James* Bowdin, Master of Dredging of tho Harbour of Montreal, was appointed to witness the tests, which wero made in the vicinity of Montreal. In Ins report Mr feodwin says the experiments were entirely successful. Ho says that after the steamer had. attained a speed of 11 miles an hour, the fins wore opened and the steam shut off, and the craft was brought to a full stop in less than her own length. Many tests of stopping the boat under different circumstances wero made, and all were said to be very successful. In Lie matter of turning tho boat with tho aid of the fin brakes, it was, found that she could very readily be reversed in her own length. In order to test tho strength of tho brakes, ono of them was opened as tho boat was proceeding at full speed, and it. successfully withstood this severe trial.

TEMPERATURE OF FIXED STARS

Some interesting results as to the temperature of a number of the fixed stare have been obtained by Mr Harkauyi, who has mado use of Vogel’s measurements of stellar spectra. . Tho method adopted is based on the fact that, as a body is heated, the most energetic portion of its spectrum gradually travels towards the violent end, in accordance with Wien’s law. The constant differs, however, with tire character of tho surface os omission, being 2.940 for absolutely black bodies, and 2.630 for polishing platinum. There is thus some doubt as to the truth of the absolute figures obtained; but the method, at any rate, permits of an accurate comparison as to tho relative temperature of stars inter so. Tho sun, it appears, has a temperature intermediate between the highest and lowest figures noted, some being much hotter . than it and others colder Axoturus and Aldobaran, in spite of their splendour, are relatively cold thentemperature being little above 2000 deg. 0. THAT WONDERFUL RADIUM. Tho “Anglo-Indian Review” summarises an interesting account of the possibla future applications of radium. Tho area where success is practically assured is at present not very largo, but in the medical field it is already fairly extensive. In the working of Xrays and in the results achieved in tho treatment of, cancer and blindness wo have every hope for great and universally benefiting results. In its industrial application wo are somewhat restricted by the extremely limited supply of radium available, but it is stated that a small fraction of an ounce properly employed, would probably provide a good light sufficient for several rqoihs and wopld not require renewal during the present century. It has been calculated that the energy stored up in 1 gramme of radium is sufficient to raise 500 tons weight a mile high. An ounce would, therefore, suffice to drive a 50-horse power motor car at the rato of 30 miles an hour round the world. DEFENCES OF PLANTS. • The reasons why certain plants are avoided by slugs and snails have boon shown by experiments to be various. Tannin, acid saps, ethereal oils, and, bitter substances prpyp to be objectionable to these creatures, and some plants are protected by acid secreting hairs. Tho carrot, which is particularly attractive to slugs, remained practically untouched after treatment with a ono per cent, solution of potassium binosalate. Certain aquatic plants were shunned by the water snails, but were speedily eaten after the tannin had been extracted. THE HIGHEST TELEGRAPH POLE. The largest telegraph pole in England lias been erected at Ilfracombe. It is to be used for wireless telegraphy experiments betueen the Alumbles and Ilfracombe. The height is 116 ft 3in, it is 17ft in diameter at the base. It has been placed at a depth of Oft in solid rock.' ; THE PARKS OF LONDON. It is said that London has no less than 313 parks and open spaces, while in •1834 : their number was onjy 103. They are reckoned to have post £5,200,000. Qn a rough calculation there is art acre to 752 persons, reckoning to Loudon a little more than 4,500,000 souls.