The Geographical Journal (Journal of the Royal Geographical Society): Volume XII, No. 2 [‎263r] (28/154)

OCEAN, AND ITS RELATION TO OTHER OCEANOGRAPHICAL PHENOMENA. 119
observation, though in reality that mean represents several observations.
In addition, there are many cases where the number of observations is
not recorded, though a maximum or a minimum temperature, or both,
are given; these have been counted as one or two observations, accord
ing as one or two readings are given. Therefore the numbers in the
preceding table are probably considerably below the truth ; but, looking
upon them as approximately correct, it appears that the number of
observations increases from the equator northwards to between 40° and
50° N., where a maximum of nearly 14,000 observations is reached, from
whence the number rapidly decreases northward. Northwards of 70°
N. only thirty-four observations had been recorded in 1894, and to the
north of 76° no observations were recorded.
But a better idea of the amount of material made use of in preparing
the accompanying map will be formed from an examination of the
table on p. 120, showing (1) the number of 2° squares in which obser
vations are recorded in the two opposite months of February and
August, (2) the number of 2° squares in which observations are recorded
in the one or the other of these two months, and (3) the number of
squares which are blank as regards observations in these two months,
between the latitudes of 60° N. and 60° S. in the three great oceans.
From this table it appears that in the 2° squares, which contain
water-surfaces, between lat. 60° N. and 60° S., observations are available
in considerably more than half of the total number in the two months
specified, while in nearly one-fourth of the total number of sqiiares
observations are available in only one of these months, and in the
remaining one-fifth there are no observations available. To be more
exact, of the total number of squares 56 per cent, contain observations
in the two opposite months, 23 per cent, contain observations only in
one of these months, and 21 per cent, contain no observations in these
two months. A fairer estimate would, perhaps, be obtained by ex
cluding the zone between 50° and 60° S., in which zone, more particularly
in the Indian and Atlantic oceans, large tracts are blank. Thus, of
the total number of 2° squares between the latitudes of 60° N. and
50° S., 59 per cent, contain observations in the two opposite months, 24
per cent, contain observations in only one of these months, and 17 per
cent, contain no observations in these two months.
Considering now the figures relating to each of the great oceans, it
appears that of the total number of 2° squares which contain watei-
surfaces in the Indian ocean between 30° N. and 60° S., 70 per cent,
contain observations in the two opposite months, 13 per cent, contain
observations in one only of the two months, and 17 per cent, contain
no observations in these months. The large amount of information
regarding the surface temperature of the Indian ocean is prominently
brought out by excluding the zone between 50° and 60° S., which is
almost a complete blank; for it appears that of the total number of 2°