i i
M f l
i t
r f l
jc e . meter, during a whole year, did not vary, at a medium,, above2o < .
I t is therefore evident and beyond all doubt, that there is no large
con tinent from 60 to 7 x and upwards; and that the inconliderable
fragments exifting there, are much colder than the lands in any cor-
refponding Northern degree.
T h e fea being a tranfparent body, the beams o f the fun penetrate-
a great way into it, but at laft at ,the depth o f about 271 feet E n g -
gliflj meafure the rays o f light do not pafs any farther, and a body
o f the above-mentioned height o f lea-water, becomes perfeffly
opaque + . Wherever therefore no bottom is to be met with at
the depth o f 45 fathoms, the fea cannot refleff any beams o f the
fun, which are abforbed, and as it were fwallowed up in the depth
o f the ocean: and as the refleffion o f the beams o f the fun chiefly-
contnbutes to the warm temperature o f the air, it hence becomes
evident, that feas:of great extent, which common !y exceed 4 5 fathoms
in depth, have never fo warm a temperature o f the air, as the lands,
lying under the fame parallel 5 and for the very fame reafon, iilands
o f a moderate fize, furrounded by a great ocean, are not f6 hot, as.
large continents fituated under the fame parallel. T o thefe particulars
may be added, the famous experiment o f the burning mirror,
whofe focus, when directed on a quantity o f water, produces no heat,.
whereas.
* Dairy rnplc’s Collcftion, and Pliilof. Tranf. vol. 66'..
+ Booguer Efsai d’Optique fur la Gradation dc la Jumiere.
W A T E R a n d t h e O C E A N ,
whereas, in the fame focus, any metal would inffiantaneouflymelt, vitrify
and evaporate;, nor can we omit the well known circumftance,
that the fun moves eight days longer in the Northern, than in the.
Southern ligns o f the zodiac. This makes the winter eight days longer,
and their fummers eight days Ihor-ter; which all together muft
cool the Southern hemifphere, by a 22f£ or very near by a 23d part
more than the arffie regions.
Cuncta gelu, canaque ceternum grandine tebla
Atque’ cevt gldciem cahibent, riget ardtia montia
JEtheriifacies, furgeniiquè obolia Phcebo,:
Duratas riefeit jtammis mollire pndnas.
S i l i u s 1 1-At.icus lib. III. v. 480,
I might Have been fels prolix in regard to the obfervations on the
ice, its formation and caufes o f the cold, had I not thought, that by
colleff ing here as it were every material circumllance, relative to the
ice in the Southern hemilphere, into one chapter, and examining
what has been. laid on both fidek o f the queftion, feme future navigators
might be better enabled to judge, how far the obferved faffs
correfpond with the-a-fligned caufes. I f they lhauld find reafons to
be o f a contrary opiniön, they will certainly be induced to publifh.
the faffs, upon which that opinion! wa:s founded; they will point
out my miftakes, and lliew the caufes. o f my error; in Ihort they
to t
ICE,
will