THERMOMETRICAL JOURNAL 197 
af thefe Iflands, the land cannet be fo cold as a northern con-- 
tinent naturally mut be. Indeed, the ufefulnefs of the ther-- 
mometer feems to beapplicable tothe more dangerous fitua- 
tions, and not to Iflands in warm climates; J fhould fuppofe,. 
for obvious reafons, that the changes. would-not be great 
about the Iflands fituated between the tropics.. The {hore 
of thefe Mlands is generally bold, and the land. being 
very high, may be feen. at a great diftance.. The 
climate is not fubje& to fogs, {now ftorms, Hlands of Ice, 
long nights, &c. fothat, except hurricanes, (which are 
more fatal to fhips in port than at fea) there feems-to be but: 
little danger in fuch navigation... 
After leaving the weftern Iflands, Captain Billings fleer-- 
ed to the weftward, being in nearly the fame lattitude on 
the 30th (37° 47° N.) that he was on the 17th of Auguft. 
(37° 53° N.) but during the intermediate time he was dri- 
ven, as winds prevailed, in.a zig zag courfe,.as far North 
as 39° o4 N. and as far fouth as 36° 26.N. It appears 
alfo during this time that his thermometer varied from 1° 
to.5° ;. but: it 1s-to be remarked .that  there-is a. me-- 
dium in his thermometrical variations. anfwering to the: 
medium of his lattitude. When he was in 39° o4. the 
thermometer marked 75° and when in 36° 26. it alfo 
marked 75° but when in 38° 12. it marked 70°.. Now 
confidering that he had the warm influence of the gulph 
fiream to the Northward, and that the ocean water to the 
fouthward muft naturally be warmer thanthat more North, 
out of the ftream, there feems to be a perfedt agreement 
between .theory and fa&t with regard to the ulefulnefs 
of the thermometer in difcovering the courfe of this cur- 
rent. The fame thing occurred in the courfe of my 
paflage in the London Packet with Door Franklin, (fee: 
Vol. 2. page 329 of the Tranfactions of this fociety) in: 
June. 
