SCIENCE NOTES,

Otago Witness, Issue 2171, 3 October 1895, Page 48

SCIENCE NOTES,

•.•Among the recent interesting additions to the magnificent Natural History museum at Kensington ia a complete cast of the iguanodon, which has been acquired by tbe trustees of. the British Mußeum by exchange with the Brussels Inatitution. T&e British Museum has possessed for some time teeth and detached bones of this primeval monster, which were unearthed at Tilgate Forest, Sussex ; at Maidstone, K«nfc ; and in other places. But no complete skeleton of the extinct land reptile has been found in this country. The ignanodon was a vegetable feeder, with teeth adapted to crußh the young ehoota and leaves o£ plants. The ske'eton at South Kensington hara height of 15fr, and is 30ft in lengl.h.

• . • If the coal mines of the world were exhausted, it would be a relief to know that other great sources of power are at our command ; that no distress would eneua with such rapidity as to deprive us of a means of warmth. In fact, our own mother country, England, has been contemplating the time when her fuel centres will have become diminished and the burrowed catacombs reaching far out beneath the ocean's bed will have been emptied of their precious deposits. Then the miner will take his pick and shovel and mount upward to the air and glistening sunlight. It will not be a useless errand to move towards the sun's light, because it is here, if all other resources fail, that we may look for greater power and wider possibilities. It is not the buried sunlight of the past ages that we need look for any more, for that is for ever gene. The heat of the Kan, the living, reviving rays of our parent planet, will yield its energy for CDuntless years to coroe to warm our bodies and light our homes. John Kiicsf on invented a machine with which he believed we would be independent of the coal Bupply, and make direct use of the heat raya of the Bun. It might have been called a sun steam engine — a steam engine heated by sunlight. The vast tracts of the Sahara or the deserts of Asia can supply heat that would generate millions of horse power in Ericsson's solar enginep. The torrent of Niagara is not comparable to the incalculable waste of power on the scorching surface of theso enormous plain?. The engineering schemes of to-day will f tde into insignificance io comparison with those that the fierce cry of future necessity will force men to execute. It would be a curious sight to ccc a fully equipped powerstation situated in the centre of a dreary waste sending its threadlike lines across the desert to heat and light some distant town, thus guiding the warm sunlight that it may glow and glitter in the motques and minarets of the Far East— Electrical Age (U.S.) • . • M. Raoul Pictet, who was one of the first to liquefy oxygen and nitrogen, saja that a drop of liquid air upon the skin fin-t turns the surface red, then blue, and that the spot extends to nearly double its original size. In serious cases, the skin becomes detached, and there is a long and stubborn suppuration. In one case, the wonnd from a drop of liquid air remained open for rm ro than six months.

• . • Stopeudoua engineering undertakings ■ are marking the closing years o£ the nine- ! tcenth century, and among them must be ! Earned the Blackwall tunnel benoath the ' Thames, now approaching completion. The first Thames tunnel, the work of Brunei, was almost useless until a railway company took posEession of it ; but at the same time It was regarded as a wonderful triumph of the eniiM-eeiV art. It cannot, however, be named in the same breath with the new tunnel which is boring its -way beneath the same river between Greenwich and Blackwall. The work has been carried out on the shield and compressed-air principle, upon a scale never before attempted, the diameter of the tunnel being more than 21ft. Its length is neorly a mile and a- quarter, of which about 1200 ft pain beneath the river, One unlookedfor difficulty wa« found la pagetog throujgfc 6 I

maBB of flint ballast which occurred nearly in the centre of the boring. This necessitated tho Binking in the river above of 10,0Q0ydf of puddled olay to cover the weak placed Tbe men who are engaged in the work ot advancing the shield and clearing away tho debris have to carry on their labours ia a chamber where the air-pressure ia 231b on tbe square incb. Ik may be noted that Brunei devised the Bhiold method of cutting tunnels, and tbat Lord Cochraoe patented the use of compressed air for tuoh operation! more than 60 ycara ago.

••• Dr J. Mount Bleyer, of New York, has advanced the view that de?th from eleotric shock is doe to " dynamic apoplexy," Ho describes the post-mortem appearancaa in a criminal executed by electricity in whosi the blood-vessels of the truck and limbs were almost empty, while those of the head and neck were distended with blood. The violent muscular contractions produced by electric shock natnrally tend to alter very considerably the distribution of the blood in the various parts of the body, and it in very probable that great cerebral engorgement, with hemorrhages into the brain substance, may commonly occur in death from electric shock. The medioal man who made the necropsy, however, would seem to overstate the case when he says that tyro quarts <*•' blood escaped when the skull was olpenee 1 There is not room in the cranial cavity fm that quantity. ' The immediate cauae of death from electric shock ia almost certainly due to stoppage of the heart, the injury to the brain hero described not being an e»E€-utial factor, thonjjh it may frequently coexist as a complication. — Lancet.

•.' Profccsor LWersidgo has been experimenting upon waterproofing brick and sandstone with oil, with a view to determine for what length of time th« 80 materials can be protected from ruoJstara by Each treatment. The general procedure was to allow the atone or biick to absorb as much oil as it would take up, and then to expose it to tho weather for a long period. The cheapest oils were employed — namely, lineced, boiled linseed, and crude mineral oil. The last seemed to give little or no protection, for it quickly evaporated. The sandstone absorbed tar less oil than the brick?, which were sound, mjichine-mado articles. The bricks retained nil the oil which they absorbed, and at the end o£ four years had not lost weight, and were quite impcrviouß to water. Bat the sandstone cnbes experimented on, although they had returned to their original weight, and it might therefore be supposed that the oil had loft them, still retained the property which tho oil had conferred upon thfm of repelling moisture. They were praoticaily impervious to water.