File:The Emporium of arts and sciences (1812) (14579612569).jpg

Identifier: emporiumofartssc02coxe (find matches)
Title: The Emporium of arts & sciences
Year: 1812 (1810s)
Authors: Coxe, John Redman, 1773-1864, ed Cooper, Thomas, 1759-1839, ed
Subjects: Industrial arts Technology Technology
Publisher: Philadelphia : published by Joseph Delaplaine Philadelphia : Kimber & Richardson
Contributing Library: Francis A. Countway Library of Medicine
Digitizing Sponsor: Open Knowledge Commons and the National Endowment for the Humanities

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is impossible, in this case, to ascertain theexact depth, as a quantity of line, equal to a b, would bepaid out, whereas the true depth is equal only to the linea c, which is much less. But the case is very differentwhen the patent sounding machine is used, as the opera-tion ceases when it has reached the bottom; nor is thestray line, a b, whatever its length, at all taken into the ac-count. It has been found extremely difficult, and sometimesimpossible, to obtain soundings in very deep water withthe common lead, which may perhaps be thus accountedfor. The common line which is used for sounding,though, if left to itself, it would sink in water, yet its de-scent would be much slower than that of the lead, sepa-rately ; it consequently follows, that the lead must be somuch impeded by carrying the line with it, that when itdoes reach the bottom, there will be scarcely any sensi-ble check to enable the seaman to know the precise mo-ment. Indeed, if he can ascertain even this to a certain
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Emporium ofJrts 8cSci*ices Vol. 2.p&4 >x,l>vc Sea Los; and Sounding Machine. 121 ^ «*.«.„, *^v «..*»,<...£, ty, he still cannot depend upon the truth of his soundings;for if there be the least drift or current, the line itself willassume a curve, similar to that of the line of a kite in theair. These two causes will always operate against theperfection of the common mode of sounding. After so fully describing the principle of the patentsounding machine, it is scarcely necessary to prove, thatit is liable to neither of the foregoing objections; and itmay be sufficient to say, that, as it will certainly find itsway to the bottom, if a sufficient portion of stray-line beallowed to guard against its being checked in its pro-gress, and the certainty of its having reached the bottommay be ascertained by the arming, there can be no doubtof the practicability of its obtaining soundings, in anydepth, and no reasonable doubt of their correctness whenobtained. From the constr

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