194 
VOYAGE OF THE POTOMAC. 
[February-j 
rain, prevail during the night. In March, the heavy rains abate, 
and the land and sea-breezes become more regular. 
It is to be observed, that in most parts of India north of the equa- 
tor, the northeast monsoons prevail when the sun is in the south- 
ern hemisphere ; but on the Island of Sumatra they are changed 
to a northwest monsoon, by the direction of the land. From De- 
cember to April, and even May, the weather is often settled and. 
pleasant in north latitude, with land and sea-breezes ; but at other 
times this wind blows strong, producing high seas, breaking in 
heavy surf along the coast, rendering it dangerous to lie in any of 
the open roadsteads. 
The currents on the west coast of Sumatra are greatly influ- 
enced by the winds, but seldom set to the north in either monsoon, 
except when the wind continues for some time to blow strongly 
from the south. When the northwesters prevail, the current sets 
to the southeast, particularly along that part of the coast which 
lies north of the equator ; while it frequently happens that another 
current in the open sea, westward of the neighbouring islands, is 
setting in an opposite direction. 
During the months of October, November, and December, it is 
often difficult to sail north along the coast from the equator to 
Acheen Head, on account of baffling northwest winds and south- 
erly currents, which sometimes extend to a great distance from 
the island. On the south of the equator, from June to October, 
while the southerly winds blow with considerable strength, a cur- 
rent is impelled to the northward, rendering it very difficult to 
work to the south. The tides do not rise more than two or 
three feet. 
While thus feeling our way among these islands and shoals, 
with the extensive coast of Sumatra in view, the reader may 
possibly expect something in the shape of " Sailing Directions," 
for the guide of other mariners.. Such was, indeed, our original 
intention, arid we had actually prepared an article for the purpose. 
This duty, however, has since been much more ably performed 
than it could have been with our present limited space and 
materials. 
For this important service, our country is indebted to Captains 
Charles M. Endicolt and James D. Gillis, of Salem, Massachu- 
setts. The former, who was master of the Friendship when she 
