206 On Capt. Cook’s Account of the Tides. [Manrcrt, 
further to the south ; and on the north, there are great obstacles 
from New Guinea, and that immense collection of islands, which 
extends almost to the continent. The waters, therefore, are 
prevented from subsiding towards the west; and as the combined 
effects of the sun and moon do not raise the surface of the open 
ocean so much as seven feet, the height of nine feet, as men- 
- tioned by Capt. Cook, evidently points out an accumulation. 
We have hkewise the precise time of high water, and that is 
a fact which evidently marks the particular tide which we have 
to consider ; and whether we are or are not able to account for 
the means by which it is produced, still the fact of the retarda- 
tion is one about which there can be no dispute. This is of con- 
siderable importance to the inquiry: it will, therefore, be best 
to consider the particulars somewhat more in detail, and then to 
deduce the conclusions which seem justly to be derived from it. 
At the time of the new moon of June 22, the moon’s declina- 
tion was about 21° north; and, therefore, when it passed with 
the sun across the meridian of the place where the Endeavour 
struck, and which was in south latitude 15° 26’, it passed above 
36° from the zenith ; the sun likewise had above 23° of north. 
declination, which carried it to nearly 39° of zenith distance. 
When, however, the sun and moon again passed the plane of the 
same meridian at midnight, the distance of the moon from the 
nadir was not 6°, and the distance of the sun was not more than 
8°. Hence the waters in the southern ocean must have been 
raised higher by their attraction at midnight than at noon. 
Again at full moon July 7, the moon passed the meridian at 
midnight with south declination of 19°, which must have carried 
it within 4° of the zenith ; and although the sun’s declination 
was diminished, it still would have passed within 7° of the nadir. 
whereas at noon, when the sun was on the meriflian, it would be 
38° from the zenith, and the moon would have been above 34° 
from the nadir ; hence we see again that the tides would hav 
been raised higher at midnight than at noon. 
The same will apply to the new moon of July 22 as was laid 
down for that of June 22; and as the moon’s north declination 
was in this last instance reduced to 17°, it must have passed 
very near the nadir, and more than compensated for the dimi- 
nished declination of the sun, the moon’s effects on the tides 
being to that of the sun as five to two. 
From the above statement it is clear, that in the open ocean of 
the South Seas, the tide which followed midnight must, upon 
each of these three occasions, have been higher than the tides 
which followed noon. Now this was exactly the reverse of 
what was observed by Captain Cook in the Endeavour River ; 
for the water there rose higher at the time of the evening than 
ofthe moming tide; but these tides occurred at about a quarter 
after nme; therefore, the high water followed the time at which 
it would have-taken place in the open ocean by above six hours, 
