SCIENCE NOTES.

Otago Witness, Issue 2895, 8 September 1909, Page 74

SCIENCE NOTES.

— Little Pickaninnies. — ■ Negroes are not born black. When a negro infant comes into the world it is white, with a yellowish tinge. It grows 'darker and darker each day until the tenth, when it is has" arrived at its deepest shade — Electric Light -in Jerusalem. — A scheme is now on foot to supply Jerusalem with electricity for light and power, so the Washington Chamber of Commerce announces, while the construction of an electric railway between that city and JarlU, is aJso being consiitered. Damascus already nas its electric tramway system, and the streets of the city are now lighted with 1000 electric lamps, provided' gratis for the Serail, the Oity Ball, and the Grand Mosque. — Invention Handicapped. — Great Britain iias, after many begrudging concessions, fixed the cost of a patent at dtJIOO. A workman in Belgium can patent any improvement of which he thinks for the nominal sum of lflfr. The exact equivalent of this in British money is fs Hid. No wonder we have ix> struggle hard to mainxain our lead i-n many lines.— Agricultural Economist. —Metal Ribbon.— The process of making metal ribbon by pouring a molten stream on a rotating drum .oas oaea wrested troui tne sea, and in Cireat only 1-IQQOin chick may be predtwed at the rate of 2500 ft per minute, and a large machine just made toaa a dozen or more noezles for giving" as .many ribbons at once. Tl»e ribbon is projected 10ft or «o, fatiing unbroken., Tiie process has been applied to aluminium, zinc, tin» lead, copper, silver, and gold. ' —Altering the Face of the Earth. — Ihe lace of the country in Europe has bi.-u materially altered by human effort, the tillable land of Holland 90 per cent. .-..•3 been wtcstsa from, tne sea, and in Grea_t . nitain a woiic scarcely le&3 great has been . .>.i3, for a third of the present land is : aid to iiave been bogs and marshes in the nine of King Alired. In the United Stales, where' the work or reclaiming is just beginning, it -is estimated that drainage will bdd 20u,000 square miles to the farm land. —World's Largest Crane. — The gigantic 160-ton crane, , which practically completes ihe equipment of inaeninery ai> i.he Devonport Dockyard (North) Extension, and is said to be the largest m the world, nas just undergone the most important of its anal tests before it« acceptance by the Admiralty irom the contractors, 3iessrs Cowans, fcmeidon, and Co., of Carlisle The crane was tested with a load of 24.0 ion* — 80 tons beyond its contract tonnage — ai-.d this load was carried with ease. Tnu immense structure, which, includes over 1000 tons of material, represents, an outlay of £3U,'JOO. "" — Drug Preservatives in Food. — Mr Cecil Cribb, the well-known publip analyst, opened a discussion 'before the International Congress of Applied Chemistry, in which lie supported thoae who advocate the prohibition of all preservatives in foods. Dr Wiley also maintained that under all conditions preservatives should be regarded as adulterants. A trace of copper sulphate in peas, its said, might not harm a robust person, but to many weakdy persons and invalids euch additions must be highly injurious. Ho supported Popular- Science Siftmgs in asserting that preservatives were unnecessary, and he wished to see them bv/ept away. — The Newest Language. — There is in use in some parts of the West Coast, of Africa, says a report, a system of writing of native invention wihich is said to be successfully competing with English •writing. It is called- the Val language, end was invented by one Doalu Bukere, assisted by five of his friends. The characters resemble Egyptian hieroglyphics, but the tongue is said to be harmonious, relatively easy to pronounce, and with a grammar that is far from difficult. It is being more and more used in West Africa, and, it is said, may become the dominant form of native speech in Liberia and adjacent countries. — Popular Science Sittings. — The Size of Ocean Waves.— The size claimed for waves in great ocean storms is often exaggerated, 'for soience has shown that the biggest wave caused by a. gale does not exceed 30ft. Tidal waves have been known to reach heights of 60ft, huit they are an exception. With the increase of siz3 of ocean steamers the point of sight of the passenger has been raised, and it requires the roughest kind of a sea to show a. broken horizon from the promenade deck of the Mauretania and her sister ship. In both, the pitch of the vessel is largely eliminated, although their decks, high above the highest waves of the most severe storms, have been washed by water thrown upward because of the opposition offered to the advance of a great wave by their hulls. On the decks of the small 4 steamers of past yeara, where the point of sight was low, the wa\es often appeared mountainous. — Popular Science Sittings. — Grass for Match-wocd. — The fact that lumber fo. the making of matches is becoming scarce lends inteiest So a report from India that a gt&s a is being Bucces&fully used for match sticks. At Sholapur » factory has been started which is making matches from ; growth called Surya grass. The glass is cut generally into 2ir lengths, winnowed and screened to obtain uniform size, and then boiled in •paraffin for five minutes, and dried id a revolving drum. Twenty-four pounds of Burma paraffin are sufficient fo.. 7000 boxes of matches. The matches, shaken through ( horizostal sifter, are deposited in horizontal layers, which are secured ir a frame •foi the dipping of th< ends, which ends are dipped in a solution of ahlorate of potash, sulphate of arsenic, bichloride of. potash, pondered gypsum, and gun arabic. Six .pounds of this mixture provide for the 7000 boxes of 80 matches each. Materials are so cheap that matches sell for about 2s a gross. —Automobile 1 Hoe. — 'A new automobile hoe has been invented wihich is designed especially for the cultivation of beets and other crops planted in tows. It has. six blades, and is driven by an explosion motor, by means of gearing. The chassis, constructed of steel angle bars, is pointed in front, and rests on four wheeh, of wlkicfc the front pair

■ ; ■■ rAmm r serves for driving. tn> icbe front of the imyjbine is . a two-<^lindef motor of 16 taorse-toowe-r -wtoioh Bttiy be adapted to burn either gasoline or oarburetted alcoh-cJ. The maximum speed of the machine is about 2ft per second- The driver sits in the centre of the* rcuaobine, but the apparatus ia so arranged that the position of the driver may be altered to suit the requirements of the work. The automobile hoe complete weighs 27501b, and cultivates a strip more than Bft in width. By the substitution of blades of special form the machine can 'be adapted to perform, rapidly and neatly, the preparation of the ground 1 before sowing, which is of so great an importance, especially in the cultivation, of l>eete. —To Baffle the Modern Burglar.— The problem of the safe custody of valuables under lock and key, in fact of the misplaced ingenuity of present-day burglars, has been responsible for the production of some very ingenious safes and locks, but all others have recently been excelled by the invention of a mechanic in New York ! It consists of a burglar and fire-proof safe which has no key, and yet retains its contents intact, subject to the voice of its owner. In place of the keyhole a mouthpiece is inserted in the safe door. In the interior of the door iteelf a phonograph cylinder and meohaniem i 6 contained, the cylinder containing a secret "key phrase." To open the door the owner has merely to press a spring button., which sets the cylinder in motion, then spealr into the mouthpiece the same key words as are recorded on the cylinder. If the spoken message is identical with the recorded message as regards accurate sound-wave vibration the mechanism, acted upon by the vibrations, immediately puts in operation a powerful spring, whicn opens the door! The obvious difficulty is that only the owner (whose record has freen taken and inserted on the cylinder oy the maker before completing the door) .can open the safe. What is to happen in case of temporary hoarseness or less of voice the inventor does not fray, nor does the inevitable death of the owner seem to have been provided for ! — Causes of Colliery Explosions. — Engineering refers to the very extensive work being carried out in order to minimisethe possibilities of explosions in mine 6. More than 2500 men have been killed in colliery explosions since 1903. The United States, in 1908, constructed an experimental station and a chemical laboratory at Pittsburg, in which shots were discharged \ ith or without tamping. Francs has continued to acoentuate the importance of the calculated temperature of the explosion — a point undoubtedly of essential importance. Professor Mente, after the Courrieres disaster, started a large experimental station at Lievin with gallery branches which can be ventilated in imitation, of actual colliery conditions. The Belgian station of Watteync and Stassarf, at Frameries, is somewhat like the ti&lsenkirohsn station ; shots are discharged, as in the other cases, into fire-damp (of 8 per cent.) and coal-dust; the "maximum charge" is established by blasting with tamping, the "limit charge" by blasting without tamping. England has recently added to the Government station at Woolwich another station at Althofts, especially designed 1 for studying coal-dust explosions and their propagation. The station is charged with a mixture of IS per cent, of coal gas and 85 per cent, of air; the tests are generally- conducted by ascertaining', not the limit charge, but the charge which proves, in, ballistic pendulum experiments, equivalent to a charge of 56 grammes of dynamite (containing 75 per cent, of nitro-glycerine). Ten. shots are always fired with 12in of clay tamping and 10 shots with a smaller charge; none of these 20 shot* must cause an explosion, nor leave any un exploded explosives in the hole if the explosives are to peas the test. AustriaHungary has two stations, Germany five, the best-known bsing that at Gelsenkirchetu. There ara many problems to be studied in connection with explosives, different tests aro not always in accordance, a-nd the recent tendency seems to be more in favour of on? summary testing under conditions imitating actual colliery conditions. But not all the stations are in a position to charge (heir galleries with methane; accidental features of the mines play too important a parr, and as blasting agents are manufactured for the markets of the whole globe, exports, add"? Engineering, have come to the conclusion that the question is not ripe for the unification of methods. — Wellcome Research Laboratoi ies. — Messrs Bailliere, Tindall, and Cox, publishers, London, have been authorised, on behalf of the Department of Education of the Soudan Government, to undertake, in future, the issue of the Reports of the Wellcome Research Laboratories at the Gordon Memorial College, Khartoum. Two volumes had previously 'been issued, covering a period from the foundation of these laboratoi ies in 1905 to 1906. The Third Report \va«s published at the beginning of the pvpent year, bringing 1 the work up to 1908 The Soudan Department of Education lias taken this step to meet the considerable demind for these Reports which has arisen amongst medical men and other scientific woikers interested in tropical research. Hirhorto only a limited number of copies has ljeon issued, and these Reports have been *-en( gratuitously to Govcrnirpani departments and to vaiious medical, *anita.ry, and other institutions interested, a* v.-01l a a to a few leading authorities on the subjects d^alt with. The ivck of ihr-c labo ratoncs-has fo far that rh* late.-t Report contains =©•• " 480 rages of detailed records of many mr- i r m^ cxj.ieriini.nt- arcl researches, principally connected wif'i tiopical medicine. This volume is profusely illustrated, and melrd-es. many -valuable coloured plates. Simultaneously with the Third Report, and a^> a supplement to it, is published a review of the progress made in tropical medicine dun-ing recent years, compiled by Dr Andrew Balfour, the director of the laboratories, and Dr R. G. Archibald. The great cost of production of these Reports, especially in then, present voluminous dimensions, necessitates making a charge for them henceforth. The price fixed is as moderate as is consistent with the cost of publication, and any profit made will be devoted by the Soudan Department of Education to a special fund foi future publications of the laboratories. All applications for current publications and for Teprints of the First and Second Reports of the Wellcom. Research Laboratories, Khartoum, should 1 be addressed to Messrs Bailliere, Tindall, and Cox, 8 Henrietta street, Covent Garden, London.