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Show SCIENTIFIC TOPICS. CURRENT NOTES OF DISCOVERY DISCOV-ERY AND INVENTION. The nifgrtt Camrre Ittf tlnlll Tlkn iku nit br rit ri A New Ulna fof DM I, h .y Wrluui IariUt.t. To Ita Tf.lh I Ike 1 rarlt. The reckless manner In which most leoplo (tun their teeth It enough lo nak their wont enemy remonstrate with them Tho nre of the teeth should bo begun In babyhood a wit tootbbruih being used twice a day by whoever ha rare of the Infant At oon a the flrtt teeth looeen the child hould be taken to a denllat to remove them, to the new teeth will have room After this periodical violin ahould be made to the dentlat A child ahould never be allowed to bite bread or crack nuta with tils teeth for It la likely to chip the enamel The teeth to bo kept In proper order and to look while and Immaculate ahould not pnly be brushed brush-ed night and morning but after every mcnl In the day The toolhbnuh must bo rather bard end you must provide younelf with two or lliree of various shapes, so as to keep the leeth In proper prop-er condition as you cannot properly clean every tooth unless you havo a brush that la especially constructed to reach the back cornera In your mouth A toothbrush should be well washed In clean fresh water and either soap or nmtnontn used now an 1 then to clean It with It must be remembered thaHo take too hot drinks or eat too hot food Is very bail Indeed for the teeth The rapid transition from heat to cold Is the worst possible thing that could happen In them and often causes cracks and disease of the teeth It ( vinegar la taken with one' food or medicine In whleh la any kind of Iron steel or any acid, the teeth not only should bo well brushed afterward but tho medicine taken through a lass tube. Moating l(Kkl. In very early daya ships of any site wero doeked by grounding them at high water and then waiting tor the tide to recede, work being proceeded with until the tide attain rote This method was Improved upon by hollo Inn out a berth or small basin and then when the water wna down a temporary dam would le made across the entrance to the latin where the ship lay so that work could go on uninterrupted by the rising tide This waa the origin of the graving dork the essential fartor of which was the existence of tho rise and fall of the tide and It Is dun to tho absence of tide that wo owo tho original origi-nal floating dock The almost tldeless shores of this country mako It tho " ! nursery of the floating dock but It wanln tho-lliltlo aea that tho first floating dock waa tried In the time of I'eter the (treat the captain of a llrlt-Ish llrlt-Ish ship finding that his vessel In Cronstadt harbor wna In want of docking, dock-ing, and that owing to tho absenca of tide, the then orthodox method was Impracticable obtained a hulk called tho Camel, and, completely removing her decks and Internal work, cut off ono end nnd lUtcd It with a gate Ho then beached his ship Inside the hollow hol-low hull of the Camel cloned the gate, and pumped the water from Its Into rlor, rr la In Ititmp I larra. The Hngllsh electrical papers are describing de-scribing the drj-oop lamp shown In the Illustration, which Is specially recommended recom-mended for use In damp places or outside out-side lighting The lamp, aro specially suited for mines, pier lighting or damp cellars, whero It hat been found that the plaster of parls softens after the lamps have been In ute for a little time. The cap It attached by means of a brats disk and Is fastened to tho glass bulb by specially prepared cement, which la thoroughly damp-proof, damp-proof, and tholcadlng-ln wires are perfectly per-fectly frto. so that the lamp has an air insulation In tho Interior of the cap It Is Important to note that although thero Is an air Insulation by using the thin layer of cement between tho bras and the gtaia It act aa a nonconductor non-conductor and consequently thero It very mueh 1st heat conducted than there would be It tha bras and glass were not Intercepted Tlio llarth Uituil licit. A writer lu Knowledge makes a vivid viv-id picture of the great belt of clouds, some 100 mile In breadth whleh surround sur-round the earth a little north of the equator. Within this belt rains almost lnceantly falls sometime In sheets, and the wind seldom stlw Ilefore tha Invention of steamahlpa, teasels bo-calmed bo-calmed In the 'cloud-belt" somotlmc drifted helplew for weeks IJven now the crossing of this belt whero everything every-thing Is surcharged with moisture la a disagreeable experience for voyagers going from the north to the south Atlantic At-lantic ocean or vice veraa The belt can be traced arrets equatorial Africa and across ft' Aj i Isthmus, and the great river Amaaon Orinoco, Niger, Ni-ger, Mle and Congo, arlae In these rain-soaked rain-soaked refloat, which are like exhaust-lea exhaust-lea reservoirs. The cause of the equatorial equa-torial cloud belt Is connected with the trade-winds nnd In the course of a year It ooclllnle north and south over a distance equal to about three times Its own breadth. Illtaeat Canirra Iter llollu At the photographic exhibition at the Crystal palace, tondon, there waa shown what la undoubtedly the largest camera ever made The camera waa over six feet high. It takes a plate alx feet by five feet but thla site can only be utlllied for lino work and ordinary copying as the Levy screen necessary for the half lone proceea can only be obtained up to about forty by thirty Incbe. It Is Intended that the back part should be built Into the partition wall of tho dark room to that the latter lat-ter would really form the dirk slide, otherwlso a holder of aufllclent dimensions dimen-sions would be oxtremely heavy and cumbersome Ily Inclosing the rear of tho camera as a dark room the plate would be placed directly Into the back part of the camera being held In position po-sition by adjustable ban which take any site from whole plato up to tho full capacity of the camera The full extension of the camera waa twelve feet, so that when using a lens of about sixty inche principal focus, It Is pos alble to copy aamo alio aa the original To provide for the uso of lensra of shorter foci tho middle body of tho camera Is provided with a plate holder and by means of a door In tho sldo tho operator can enter Thla part of the camera forma a little room about seven feet by thrco feet In whleh at least two persona can aland and watch SPlUnfe tho operation of focusing tha Image nnd exposure The lens fitted to this camera la of the symmetrical type, specially spe-cially mad for copying purpose. It work at Ml nnd has an equivalent focus of sixty Inche Tho prince of Wale Inspected this remarkable camera cam-era with much Interest I Irrtrte Milt Drlltrry. Ii Geneva a novel system for delivering deliv-ering letter In high apartment house Is to bo tried On the ground floor Is arranred a cabinet having as many compartments and boxes as there are floor In the house, When a .Inter Is deposited In any box. It mnkea a contact con-tact which ring n bell cm the corresponding corre-sponding floor The bell ran only be stopped by the removal of the letter The samo current that rlngi the bell opena n valvo connected with a water lank In the top of the house Hero are located cylinder attached by rorda and pulleya to the letter boxe and to arranged ar-ranged that when they nre Oiled with water they will aervo to haul up tho letter box nnd Ita content to the proper prop-er floor When the box nrrlvc the letter let-ter Is automatically dumped Into a ata-tlonary ata-tlonary reeeptaclo and nt the same time the cylinder Is discharged of Ita water. The letter box then descends to tho lower low-er floor tho bell slops ringing nnd It remains In position walling for the next vltlt of the postman IrrgfrtKchrnr(trr Itlfl. Here Is a toy for the navy one which some of the navy' men would enjoy playing with In tho neighborhood of tho Bpanlah flotilla It la a Drcgget-Bchroeder Drcgget-Bchroeder alx pound rifle It can flro thirty-three shota a minute and Its projectile pro-jectile can pierce three Inche of elect nt a dletanco of three miles It Is n new gun which hat Just been placed an the revenue cutter (Ireshatn It will be In charge of flunner l'lnn, who has been on the old cutter Andrew An-drew Jarliaon and on the Oresham for twenty-six )rs. Tho Urealiam hat only ono slx-pounder rifle but she could easily Increase her armament by four or five more She has a speed of twenty-ono mile an hour Hut her chief weapon of offense Is her torpedo tube Hunting Meal. Slnoe Mr C I! Trlpler of New York baa perfected hla npparatua for liquifying liqui-fying air scientists havo been able to make curloua experiments at the liquid air can be secured In large qiisntltle aaB the Scientific! American When a dishful of tho liquid ulr It dipped from tho can It bolls so violently that drops of It aro projected tome distance The liquid la blue In color, and a burn from It takes about six months to heal The plcturo shows how steel may be Ignited In the liquid oxygen It la only necessary nec-essary to stick the point of a steel psn Into a match light It and thrust the whole Into the liquid air to furnish sufficient beat to communicate the lire to the stesl The Nnn't IUjti. It Is estimated aaya Selene Sittings, that the earth receive not more than one thousand-millionth part of the total to-tal radiation of the tun's rays If any considerable proportion of this beat were concentrated upon tho earth It would not only become uninhabitable, but become speedily consumed It the great accumulation of Ice at the north pole wero p.oced at a point on which thla tremendous heat could be focused It would melt at the rate of 300 000 000 cubic miles of solid Ice per second, and the beat la estimated as mechanical energy, en-ergy, it the rate of about 10 000 horsepower horse-power to every equare foot of lurfaca. |