HYDllOGRAPHICAL NOTES. 
171 
thorns, the flag was carried out NE. by N. ; at 15 fathoms, 
the same. I tried this experiment again the same day, and 
found the surface-current to set E. by S. 7 miles ; at 10 
fathoms, E. | N. : at 13 fathoms, NE. | E. ; at 15 fathoms, 
the same. Again, in Lat. SO" SS' S. Long. 13° 40' W, 
purrent on surface E. by S. 14 miles ; at 10 fathoms, NE. 
byE, 
5. Range of the Barometer at St Helena. 
At St Helena, during the many months which I had an 
opportunity of observing the barometer there, I never have 
found it range more than .45 parts of an inch : the two 
extremes are 30.^5 and 29-80. The usual height is from 
30 to 30.10. The wind here varies very much with respect 
to its strength, but seldom above a few points in its direc- 
tion. It seems to be affected a good deal by the moon ; 
for I have always observed, and bad my observations con- 
firmed by all the ships on the station, that, at or near full 
moon, there are light winds: and at the first and last quar- 
ter it blows strongest. At all times, it blows stronger 
about noon than at any other time of the day. 
6. On the Phosphorescence of' the Sea. 
I shall only mention one observation, which induces 
me to believe, that, in some cases at least, the shining 
appearance observed frequently during the night in the 
ocean, is occasioned by phosphorescent animalcula. In 
September 1816, in Lat. 4" 59f S. Long. 9" 19' E., I ob- 
