SCIENCE and INVENTIONS.

New Zealand Herald, Volume LVII, Issue 17471, 15 May 1920, Page 6 (Supplement)

SCIENCE and INVENTIONS.

SEABOHUOHT OOHTEOt. js] It has been fonnJly,experience that an ■I-; observer operating a military searchlight v- finds it difficult to train the searchlight on. the target^hen- he ,is stationed close . to the searchlight itself. The reason for this is that the observer at the lamp » handicapped by the dazzling effect 'of the |HN . "bright beam* on the w eye. On www* ;:vv; ; if■,this feature of searchlight operation, ;,'V- remote-control schemes have been devised .'tvhcrebv the observer is stationed at a '■>'' : distance of some 600 feet from the search- '.;'■': 'light itself and^th*re lVl trains the lamp, £.» '■■' upon the target by mean's of electrical V;• • • control. ~..r S *. '" R' I' A THE HOMI , ZOO. .... ■ ■ ; * The zoo for every nursery, with lions ••*.• which roar.'canaries that Ring, and ducks '- - that reallv'qua«k is the latest outcome of gramapliunie invention. It is the invention of a young Englishman. Another form m lhe.vtnlkihg.toy, is the story-book which £ tells its'own story.-: These books are lull a picture*; and..one can be placed on ant-machine. The animals or birds are of 'cardboard, and contain, like the dook*. a flexible disc record. . The performance in every case is to a musical accompanii '' rient. 'Little 80-P€ep tells why she has lost her Sheep, anil the mocking-bird mocks to the l^rcars'iiua,most effective manlier. Thosg.tovs- have great educational possibilities, mid on Olio backs of the pic- . v' tuns nre short natural history stories. ONE-PIECE CONCRETE HOUSES. ■ Somoyeara ago Thomas Edison invented a method of pouring concrete into a single mould and turning out a house. This scheme, much ridiculed »t the time, nas progressed. Fourteen four-roomed, twostorey houses of this type have just been competed at Union, New Jersey, ami tiventv-tive four-room, and fifty sis-room, « two-stortT houses are being bialt at Phil l'psburgh'New Jersey. The basic idea is that of die castings. Sectional, standardised, heavily-built-up. wooden forms are so made that they form a mould, as though 'a pattern house bad. been moulded inside » .. them and .'ft*-withdrawn. \fliev are painted with fan lead and oiled before . • {£>. -This mould is then filled with molten concrete, instead of the molten metal used f* : in metal' tastings. The forms are then • removed and set up for the next house. A' BBIfABKABLE TREE. ' i '< -There flourishes in most parts of. the Australian continent, especially in West- ;" ern Australia, . a species of Australian I'' ■' grass-tree known as the blackboy., The '" v peculiar interest of. this tree, which grows to a normal height of from seven to ten feet, is the variety of commercial purposes ~"• Mi which it can'be put. The tree contains gum, in large quantities, and among ' other by-products extracted under : treatR. * ment are tars (free from harmful acids), £ -tarpaulin dressings, rope and sanitary c-" tars, lacquers : {such as Japan black), :' steam and refrigerating pipe lagging, v paint for ironwork that requires sieving ; ■ •at high temperatures, stains and paints; ' phenol, benzol, and alcohols, coke, pot■v; *." ash, and pyrogeneous acid. Not only I. .have all. the articles already enumerated *>■ been obtained, but a company recently ■ * formed to evtract them also intends t<' ft- ;' produce dyes, perfumes, and formalin, and' ;■; . " various kinds nt varnishes. y MAKING PHOTOPLAYS AT NIGHT. . f-i - .. ' "Most modern cinema- studios" are proSi, ?'. vided with mercury-vapour lamps on over- ": - V"' head racks and floor stands, so as to give any kind. of Humiliation desired. The £ Overhead racks-; are- suspended from a S ; steel-beam framework that travels along *»,% v'on; the side rail*, so as to bring the ... * lamps over any part of the studio floor. • ;1 r While flaming, arcs are still used in some { "' studios, the mercury-vapour tubes to-day " are predominant' for many., reasons. The V...' ' luminous element of the latter type of ?~ lamp is a luminescent arc; in a'highly V- ' evacuated tube "of "glass,"* formed between ;,v a mercury cathode and an anode of mer- ',"_' cury or" other metal' not attacked by it. The large output of actinic radiation | . from mercury-vapour lamps gives them |g . special advantages in, the fields of photo- ''•"''■ graphy'. Although the light from the s- -J mercury lamps. is a ghastly green, which '■.'- is'', most unpleasant and distorts all col- \ ? ,; -';V oar, schemes, it is relatively comfortable ; for the actors, and excellent from the P f- photographic point of view. «*;<■• ***" v %: ■;'»' J" < '-M-1' ' I ■ —■■ / .