JB/169/108/004

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the most original part of the experiments: but being finding himself unable
to put them into any sort of form, he applied to
my Brother who suggested among fresh experiments, &
put exhibited the small gave an account of the whole in the form
in which it stands at present. He has made it
about three times as short concise as it was originally,
by digesting the result of a the greater part of the
experiment into tables. Nairne has found out
that the extraordinary degree of exhaustion appearance of perfection of Smeaton’s
Air-Pump, as indicated by the Pear- Gage invented
by Smeaton⊞ ⊞ (It is called from its shape the Pear-Gage) is in good measure as to the greater part of it fallacious.
Nairne and my brother together have found out the
cause of it the deception. As the air is exhausted drawn out of any Air Pump the vacuum
is supplied by a vapour that is discharged emitted from
the wet leather or other moist substances that
must almost unavoidably be in used for keeping the
receiver tight fast upon the frame. This vapour
is recondensed upon the admission of water: which
air is not. One sort of gage in consequence exhibits
the quantity of elastic vapour of all kinds that is
in the vessel: another only the quantity of uncondensable
elastic vapour; that is of air.

My Brother intends publishing his papers
under the Title of Essays on the Marine, containing
boat Disquisitions and Hints relative
to the advancement of the Marine Service in
general and of Ship-building in particular. He thinks
they will stand a better chance of being read in
print than in Manuscript. If by that or any other
honest means he can get employment in his own
country,

Identifier: | JB/169/108/004 "JB/" can not be assigned to a declared number type with value 169.
Date_1		Marginal Summary Numbering
Box	169	Main Headings
Folio number	108	Info in main headings field	letter to foster petersburgh
Image	004	Titles
Category	correspondence	Number of Pages	4
Recto/Verso	recto	Page Numbering	f17 / f18 / f19 / f20
Penner	jeremy bentham	Watermarks	[[watermarks::l v g propatria [britannia motif]]]
Marginals		Paper Producer	caroline vernon
Corrections		Paper Produced in Year
Notes public	letter 248, vol. 2	ID Number	56928
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