FLOATING BOTTLES

Evening Post, Volume CVII, Issue 10, 12 January 1929, Page 18

FLOATING BOTTLES

TESTING SEA ; CDEBENTS VVORK OF HYDROGRAPHISTS The report, of the. .finding, at; Double Island Point, on-the Queensland- coast, 1 of a sealed bottle.containing a message' 1 from the .United States Hydrbgraphic Office, Washington, brings to,mind the valuablo work being done by the Hydrographie Departments':';'of the ' various Admiralties, the work"'of determining the course and rate of flow.'of- ■ ocean .'currents, writes Ewen'E; Patterson in :the "Sydney Morning Herald.".'''•'■■ : ■There arc two'kinds'of clirrents, surface currents and deep:sea' currents, and for testing-each "of them bottles are largely used. For the; -surface -''cutronts, the bottles-are generally; about ;the size of ordinary, pickle'bottleSj ■ and are securely sealed. 'BefPi-e. the-bottle is closed a. paper is'plaeed-inside'bear-ing the exact latitude and longitude rof '. the.spot.where it:is' 1 thrown into- the :water, also the• date,' "and a. "request printed in many, .languages.) that the' finder will returnl ;'• the . paper ' to -the Hydrographic Department named thereon, ■ .with full ' particulars ':&&■;■ to' '•' when : and.wher« •the::bottle';was:found.-': When a sufficient 'number :>:of. these : papers, come to hand, .vthe! • Hydrographic' Dei partments .'are enabled'"tovtearn" lauch about ocean-currents, ■'-■ ,;' -i •;'■' .'. ;■■•:

'■ As can be ..expected, many. : bf'' the bottles travel.great distances' .'before being picked up. A few. years ago, a bottle was thrown from the American steamer; Cherbkeejiwhen off the coast of Carolina, and; it .was , found 1698, days later on Nassau Islands'in the Bahamas. It .had drifted 6000= miles, ,the. longest drift on record, and- th'ad. practically circumnavigated . the globe,-, and its average rate of--drift was 3-i miles per day. Its rate of drift s was Very .slow when.! compared;:with •■the-.fastest 'drift on record. This was . achieved by a bpttle cast into the sea off .Cape Rice, Newfoundland, fjom the same' steamer Cherokee. ■ Precisely-.three, months later this speedy drifter: was 'picked iip on the Elbe Eiver, lit. Germany/after, having travelled:; 2400,..mi1e5,at the.rate, of 26 miles per day,-: -„;■■,■':'• •■<• •'During one- period 1- ovey-5000 bottles were-thrown into;thb.Sea,: at'.';'the: mr stance of the j Hydrbgfaphic. Office, Washington, but of.these,only 350 were returned with details, as to when and where "they, were found. '• ...;,".',' •> f, , In one year the .Australian Government, through the' Government astronomer of New South Wales, launched over 400 bottles in the -Southern Indian Ocean, but only $6 of these, were recovered. One.was-ithrown into the.^ea off- Cape Horn, in. South. America, and from there it made its way to Ashanti, on the | west coast, having travelled a distance of 5350 miles at 1 the; rate of ten miles per day. . ■/',.,,.■ '„. ", . The bottles usedfor testing the deepsea'..currents are much : stronger' than those used for the.'^Urface^'cun-entsy to enable, them •:- to .resist "•.-.the " .pressure. There is just enough air put into the bottle to allow-it to, float, a length,of copper wire, heavy ■ enough;to. make it syikj being attached to neck, of th,e bottle. -The purpbse.'of 'this,is' . shpwn when the wire, touches the ..bottom.; of the sea, for .the.•■'bottle., "is relieved of some of the weight and:, ''cpnsequerEtly trails along-about..a,;fopt or so ,abpye the sea bed, to ■wherever,.the, '.current take it. The.bottle in triia ease also.eo.ii.^ tains, a request for'its' return ..when found, but this is very seldom, as only about 20 per cent, of bottles sunk have been recovered. Not' infrequently 1 one may be washed up on a beach, or fished up by a trawling net. -V.One deep-sea bottle,which,was thrown. overboard ,at.i V.Southampton,-. England, drifted foiv.-.j^o.. jjears^^ftvideitly;, carried by the Gulf '''Stream,* jEor'.iiwas ultimately found on'the Donegal Coast of Ireland. '■ ; ■ ' ■',':'. ."■' A report of every bottle;fouud is duly entered in the records of the 1 .various countries, and from time .'to.time inforination hitherto-unknown is: added jto the -many books'- 1 and; chai'ts on-'the.; subject'of ocean cUi'ffents; ' i.'; ;.-' >■;<::'-;■'■'■? ■■-.'■