NARRATIVE OF THE CRUISE. 
647 
yet been satisfactorily determined. On the Current Chart of 1872, it is depicted as 
issuing from the Sulu Sea through Mindoro Strait ; but it is highly probable that only a 
small portion of it is derived from that sea, the greater part being the continuation of the 
current which is known to set to windward in the middle of the China Sea during the 
northeast monsoon. This weatherly current in the centre of the China Sea, extending 
from the Natuna Islands certainly as far as the North Danger, appears to be caused by 
the resurging of the water driven into this sea by the wind ; for it is known that along the 
western shores of the sea a very strong current, amounting at times to 60 miles a day, 
runs to the southwestward, that in the southern part of the China Sea the mean level of 
the tide is higher in the northeast than in the southeast monsoon, and that from this 
cause the stream is almost constantly running out of the China Sea through the Straits of 
Singapore, Banka, Gaspar, and Carimata. These facts being known, and also that a north- 
east current is met with in the centre of the sea, it may be inferred that the straits lead- 
ing from the China Sea to the Indian Ocean are insufficient to relieve the southern part 
of the China Sea from the head of water accumulated, and' consequently the weatherly 
current is established in its centre. The existence of this weatherly current was well 
known to the captains of the old opium clippers, who always worked to windward in 
the neighbourhood of the reefs ; and the mail steamers, in their passage from Singapore to 
Hong Kong during the northeast monsoon, now take advantage of this weatherly set, 
and keep just west of the reefs which form the eastern boundary of the main route 
to China. The tracing of these currents would be a most interesting work, more 
especially as to whether the Luzon Current joins the stream running northeast along the 
east coast of Formosa. 
Manila to Zebu. 
On the 15th January the Expedition left Manila for Zebu, passing through Saint 
Bernardino Strait, where a small Spanish station was noticed on Santiago Point. On the 
16th a sounding and a trawling were obtained in 700 fathoms in Romblon Strait, and 
on the 17th in 11 fathoms east of the Gigantes Islands. After passing the Gigantes 
Islands the ship proceeded north of Tanguingui Island, and then through the channel 
between Malaspascua and Chocolate Islands, round the north end of Zebu Island. Gato 
Island is pyramidal in shape, about 150 feet high, Chocolate Island is also conspicuous, 
Malaspascua is low, as is the north extremity of Zebu. 
On the 18th, at 1.30 p.m., the vessel arrived at Zebu, and anchored in 10^ fathoms 
off the town. Steering towards Zebu Harbour from the northward, it was noticed that 
Baguey Point, when first seen, looked like an island, as there is upon it a round-backed 
hill about 150 feet high. Mactan and Olango Islands are both very low. 
When the ship entered the port, the edges of the shoals were by no means readily 
(narr. chall. exp. — vol. i. — 1885.) 82 
