Rensselaer Union, Volume 1, Number 6, Rensselaer, Jasper County, 5 November 1868 — How deep. Sea. Soundings are Made. [ARTICLE]

How deep. Sea. Soundings are Made.

The difficulties in soond&g great d Cpctt* nnt. v «*y SttewV/ feJMMigUt til. twine used was s« lig^TTTiat when « certain d#|rtl*.*a* rvi>< hed it* Jbuova>C*‘wu« tha’ lead. It became on mi* account necessary to improve it* qonlity and of sea watff*, "W same time it should have enough strength to sustain the weight used In winking tho cast. T wwie whs ah ah 1 peas footed until it wn* able to sustain a ing only one pound? VVHb IHJWtwine having'll 32jp4u*4 shot atj tacked, very much greatftv. ) than bud been previously poysjb'o were reached. Small wire tips been usod’in lieu of twine, aodwd'belGMie the line need by Lieu ten ani man, of tho Warner Avetie, /!»>• soundings in the Gull 1857, w»en ho reached bottom at a depth'of 4ytßo falfirfm's,' itfbYo’ ttihii" live miles, and in one case 6,000 fathoms, a depth of seven and ©not half miles, woro reached wiiH<¥ittouching bottom, was partially eoTO;, posed of wiro. Tho seeopd difTioulty was the determining the precise moment, at which thd weight rnhWl-’ cd the bottom. It was found; thht whon the bail bad reached tb*.bottom tho lino would continue t.Q out, being *cted upon by thq ( force of deep sea currents. The'shock could not be felt at great depths, and thus it wai necessary to deviao some method by which thin important detail should bo made determinate. If a lino bo made last to ono side of a river, carried across ami allowed to trail on the water, ItwHl run out rapidly from the sida where t it is not fastenod. In sounding when tjhe ball reaches the bottopaj tha same thing occurs. The ball becomes immovable while the under entrants acting upon the lino carry .it rppidly out; So long as thin dif* ficulty remained nothing could bit), ascertained. And still another tjift;, ficulty was discovered. Tho counter currents toade bights In the lific, so that tha length of the line i+w* out was not a correct indication «fi the depth reached. These difiicultioß were overcome/by the indentions es Brooke and Massejr. Tho former invented a self-detaching apparatus by which the^.’weigh* when it reached tb© bottom would h» iimtnntly ruloased. Attbnmpo.. time a small portion of the bottom would adhere to light hollow tube* attached to the line,' i*c that When recovered the character of the bottom could be ascertained. Tho latter invented a small instrument by which the exact vertical distance traversed by the weight in Its descent would be indicated. Thb form of tho lead was subsequently» changed to a doubleooae about two. Teat in length, having its greatest . diameter four inches from tho lower ond, and tapering from this point tb tho top, where it was about two inches in diameter. Through tb© center of tho lead, which weigbod .-, from odo hundred to on* hundred , and fifty pounds, ah iron shaft tended. In the hollow at thi tower' end pioceaof quill barrels were sorted, which penetrating intd thw bottom retained a portion. When this aparatus was used on tlietlenmor Arctio by Lieutenant Berryman, tho detaching apparatus of Brpoke wa9 dispensed with as Masiby’a sounding machine was sufficient -?leterTinno'ttro'ffqirtr'wln?n-CTronglr line was run out to render it absolutely certain that tho bottom had - bee nre ached. Dciteal e ■ vetpregre*--tering thermometers wcro-nls© i»t-< tached to the apparatus, by mcaua of which it was ascertained that the sea was much cooler at great depths than near the surface. With this apparatus the deep sea sound* ings wo have described were made, and there is no doubt that they, were vory nearlycorreot. —Scientific American. i . : . » ■-»