88 



HYDROGRAPHY. 



a westerly current of 10 miles per day. The Marianne Islands lie 

 north and south. Vessels generally pass to the northward of Grigan 

 and between it and Assumption ; but I think, if there is no necessity 

 to sight them, that a quicker passage may be made by keeping a 

 degree or two farther to the north, as the winds* are undoubtedly 

 more or less influenced by the high land of this group. In our route 

 we went between Assumption and Grigan, and over the position 

 assigned the Mangs by Freycinet. It is not a little singular that the 

 position of these rocks has been laid down to the south, when in truth 

 they lie to the north, of Assumption ; and that this error has crept 

 into the work of one so generally accurate as the above celebrated 

 navigator. As far as I have examined and made search for them, 

 there are no rocks or shoals existing south of Assumption, and 

 between that island and Grigan, and I am quite certain the Mangs 

 have been erroneously placed. 



We were 11 days from the Ladrones to the Bashee Islands : this 

 was in the first part of January. We found the winds variable, gene- 

 rally from the southward, but veering several points, with frequent 

 squalls of rain — what would be termed unsettled weather, and desti- 

 tute of any resemblance to the trade-winds — until we approached 

 within a short distance of the Bashee Islands ; then we took the north- 

 east monsoon. The current from the Marian or Ladrone Islands to 

 the Straits of Balintang was north 72° west, 1\ miles a day. The 

 cause of the variable winds and absence or interruption of the trades, 

 on the route between the Ladrones and the China Sea, is to be ac- 

 counted for by the prevalence of a southwest monsoon between the 

 Marianne and Philippine Islands, which encounters and interrupts the 

 northeast trades, on the parallel of 19° north. 



Our route to Manilla, along the west coast of Luzon, was made with- 

 out difficulty, although somewhat delayed by light winds. The en- 

 trance to the Bay of Manilla is often tedious. The channel on the 

 north side of the Island of Corregidor is the best, the winds being 

 more regular and stronger. I made a mistake in beating up in the 

 south channel, which, through having more space to beat in, I am 

 satisfied is not so good as the north, particularly as greater advantage 

 is to be derived from the tide, which sets strongly through the latter. 

 The " inbat" or sea-breeze generally prevails in the afternoon, or from 

 11 A. m. until after sunset. 



A vessel may anchor anywhere in the bay. There are some shoal 



