_ NATURAL HISTORY OF A GUANO ISLAND. 171 
Wind :—In the beginnitig of October the wind was generally 
light east with calms, and the north-east trades began about the 
middle of the month, varying from E. to N.E. till the end of 
ebruary, when light winds and calms again occurred, followed 
by S.E. and E. trades till October. The only exceptions to this 
January, 1869, the wind was strong as 
not large enough to check the trade wind, so that at mae there 
was almost always a dead at the west en 
‘ occasionally a barely perceptible movement from the sea 
The set of the currents round the island was ae at A 
same ted that the wind changed from N.E. to 8.E., and t 
change was marked by the movement of an immense mass: 0 
rming the west beach. In the beginning of March the 
sand began to accumulate on the beach and continued to do so 
until the beginning of October, forming a beach about 120 feet 
wide by 9 feet high, and a mile long. When the sun crossed 
the zenith of the island almost to a day this sand began to move 
to the south, where it was piled up for some distance along the 
south beach ‘andl all that the waves could reach was removed, 
aed it was again brought back as soon as the sun crossed the 
nith going north. In a great tidal disturbance in the end of 
Weceaiihor. 1868, the greater portion of this sand was washed 
away into deep water and disappeared. 
The tide rose at springs about 2 feet, and it was high-water 
about 4 p.m. at the full and change of the moon, at which times 
there was generally a heavy swell om the west beach, and either 
the south or north according to whether the trades were N.E. 
or S.E.—the swell being on.the opposite side to the wind. 
The zodiacal ao er anes always to be seen, but was not 
noticeable for brillia 
green weed 
i ; and seemed ng to soon cover the 
we of th ‘the reefs, ab 8 ig oven andi killing tims corals. 
