388 VOYAGE OF THE POTOMAC. [May, 
CHAPTER XXI. 
The Potomac sails from Canton — The Bashee Straits — The northeast tradewinci— 
Cause and description of the tradewinds — Periodical winds — Monsoons — The 
. sirocco, the simoon, land and seabreezes — Perennial and variable winds — An East 
India voyage ; its natural facilities — Period for commencing one — Reflections 
arising from the subject — ^Arrival at the Sandwich Islands. 
A FEW days after the return of our officers from Canton, the 
frigate having, in the meantime, been completely supplied with 
water, provisions, &c., got under way at Lintin Bay, and pro- 
ceeded to her former anchorage off Macao, from whence she 
proceeded to sea on the following day, with a light breeze and 
pleasant weather. The breeze freshened as she cleared the land, 
and long before nightfall, the sky had become overcast with thick 
black clouds. The Potomac was now dashing along at the rate 
of eleven knots, with her yards nearly square, when a light was 
discovered almost directly ahead, and in the next moment the 
frigate was alongside of a large vessel, moving with almost equal 
rapidity towards the bay we had just left. The thickness of the 
atmosphere had concealed the two vessels from each other iintil 
their proximity had become somewhat perilous to both, for a few 
feet more would have brought them in contact ; and such was the 
velocity with which . they passed each other, that the hurried 
inquiry of "What vessel is that?" was lost to the ear of all 
but the interrogator. 
Onward flew the stranger, and with equal speed forward dashed 
the Potomac, as if ambitious of redeeming the time she had 
spent in the waters of the " Celestial Empire." Her course 
was laid for what is called the Bashee Passage, a well-known 
outlet from the Chinese Sea into the mighty Pacific, formed by a 
chain or cluster of numerous islands lying to the south of For- 
mosa, about ninety miles east of Canton. The island which 
gives its name to the whole cluster, of which it is the most eastern, 
is of a circular form, six miles in diameter, and has a town on it 
©f the same name. Its productions are plantains, bananas, pine- 
