titude, is
perhaps as temperate and tolerable as any part of the globe; since we,
in ranging it along, did not once meet with such warm weather as is
frequently felt in a summer day in England, which was still the more
remarkable, as there never fell any rain to refresh and cool the air.

The causes of this lower temperature in the South Sea are not
difficult to be assigned, and shall be mentioned hereafter. I am now
only solicitous to establish the truth of this assertion, that the
latitude of a place alone is no rule by which to judge of the degree
of heat and cold which obtains there. Perhaps this position might be
more briefly confirmed by observing that on the tops of the Andes,
though under the equator, the snow never melts the whole year round;
a criterion of cold stronger than is known to take place in many parts
far within the polar circle.

Hitherto I have considered the temperature of the air all the year
through, and the gross estimations of heat and cold which every one
makes from his own sensations. But if this matter be examined by means
of thermometers, which are doubtless the most unerring evidences in
respect to the absolute degrees of heat and cold, the result will be
indeed most wonderful; since it will appear that the heat in very high
latitudes, as at Petersburgh for instance, is, at particular times,
much greater than any that has been hitherto observed between the
tropics. Even at London in the year 1746, there was a part of one day
considerably hotter than was at any time felt in one of the ships
of our squadron in the whole voyage out and home, though four times
passing under the equator; for, in the summer of that year, the
thermometer in London, graduated according to the scale of Fahrenheit,
stood at 78 deg., and the greatest observed heat, by a thermometer of the
same kind in the same ship, was 76 deg., which was at St Catharines in
the latter end of December, when the sun was within about 3 deg. of the
vertex. At St Petersburgh, I find by the acts of the Academy, in the
year 1734, on the 20th and 25th of July, that the thermometer rose
to 98 deg. in the shade, or 22 deg. higher than it was found to be at
St Catharines; which extraordinary degree of heat, were it not
authenticated by the regularity and circumspection with which the
observations appear to have been conducted, would appear altogether
incredible.

If it should be asked, how it comes then to pass, that the heat,
in many pla