32 
plentifal fupply of frefh air was commu- 
nicated, that Dr. Halley himfelf with four 
companions remained underneath ten fa- 
thoms of water for 2bout an hour and ahalf, 
without experiencing the leaft inconveni- 
ence. Other improvements have fince 
been made on this bell by a Swedifh en- 
gineer, whofe name, at prefent, I do not 
recolie& 5; but the diving-cheft ef Mr. 
Smeaton would apsear to poflefs advan- 
tages which render it fuperior to every 
other machine hitherto employed in this 
country for fimilar purpoles; one of its 
peculiar excellencies is, that the diveis 
are {upplied with a conftant infiux of air, 
by means of a forcing air-pump, in a 
beat on the furface of the water. 
The fate of Mr. Day, which was, 
doubtlefs, occafiohed by his ignorance of 
hydroftatieal principles, and that of the 
late ingenious Mr. Spalding; who had 
contribuied much towards the improve- 
ment of the diving-bell, and who fell a 
facrifice to the négligence of his attend- 
ants, at the Kifh Bank, in Ireland, as 
well as fimilar accidents, feem for a time, 
to have reprcffed the fpirit of enterprife 
in thig country. In America, however, 
fo early as 1776, a very ingénious diving- 
machine, or fub-marine veflel, was con- 
ftructed by a Mr. Buthnell, of Connec- 
ticut, of fueh a fize as to contain the 
diver, and air fuficient to fupport him 
thirty mintites without receiving any ad- 
ditional fupply from above. At the bot- 
tom of this boat, oppofite to the en- 
trance, was fixed a quantity of lead for 
Dallaft ; at one edge, which was exaétly 
before the diver, who fat upright, was an 
‘ear for rowing forward or backward, and 
at the other edge, a rudder for ffeering. 
Ain aperture at the bottom, with its 
valve, was intended to admit water for 
the purpofe of defcending ; and two brafs 
forcing-pumps ferved to eject the water 
from within, when necefiary for afeend- 
ing. At the top was likewife an oar for 
the purpofe either of afeending, defcend- 
ing, or continuing at any particular 
depth; a water-gaugé, or barometer, dé- 
termincd the depth of the défcent; a com- 
pats directed the courfe, and a ventilator 
within fupplied the vefiel with frefh air, 
wWiren on the furfaee. Behind this fub- 
marine veflel was a place above the rudder 
for carrying a magazine containing fifty 
pounds of powder, with the apparatus 
ufed m firing it, conflruéted nm fuch a 
manner as to run any propofed length of 
time under twelve hours, whén it un- 
pinioned a firong lock, (refembling that 
On Subagqueous Navigation 
[Aug. ts 
of a gun), which gave fire to the powder. 
This apparatus was fo pinioned that it 
could not poflibly. move, till, by eafting 
off the magazine from the’ vefiel, it was 
fet in motion. Fora more particular de- 
{cription of this veflel, fee the lat volume 
of the Tranfaétions of the American Phi- 
lofophical Society, or the 45th volume of 
the Repertory of Arts. 
Some experiments, which were made at 
Connecticut, fufficieatly evincé the nature 
and ufes of this fub-marine vefiel, and 
that it did not afterwards prove deftruc- 
tive to a number of the Britifh vefiels, 
néar Governor’s Hland, ahd in Hudfon’s 
River, is not afcribable to any defett, ei- 
ther in its ptinciple or cenfruétion, but 
to fome extraneous circumftances, which 
it would be here ‘wholly unneceffary te 
relate. . 
Mr. Bufhneil’s invention, whilft it de- 
prives Mr. Fulton of every claim to be 
confidered as the original difcoverer, at 
the fame time fufficiently fhows to what 
a degree of perfection fub-marine navigae- 
tion may be carried, The recent difco- 
veries in chemiftry, particularly that of 
Dr. Prieftley, by which oxygen, the only 
refpirable portion of the atmofphere, can 
be obtained, in fuch abundance, from va= 
‘rious metallic oxyds, as manganefé, inié 
niums, &c, might, perhaps, be fuccels- 
fully applied to the itill farther imprével 
ment of this art; if, indeed, any mode 
could be difeovered of difengaging the Vital 
air from thefe bodies, without the aid of 
heat, it feems highly probable that wae 
rious fub-marine projects might be ufders 
taken without even the neceffity of rifing 
occafionally to the furface of the water, 
and with, perhaps, lefs rifk frony atci- 
dent, than-in the ufual mode of navigation. 
When, at theconclufion of a ten year’s 
difafrous war, we find a military tyranny 
eitablifhed in the heart of Europe, the difs 
tinguifhing feature of which is charac- 
terized by a defire to deprefs this country, 
the only power that can now effedtually 
voice of philofophy, and to view, with the 
apathy of ignoraicé, thé improvement of 
an art, edpable of being employed for the 
molt deftruive purpofes of warfare, and 
againft which, in che uffortunate event of 
a new rupture, neither the moft diftin~ 
guifhed valour, nor the greateft fkill in 
naval taétics, cotild prove of the lealt 
‘avail. 
“Te the brief thetehy which is here siren, 
