APPENDIX. 529 



The course pointed out is intended to lead you, by the time you 

 reach the coast of Japan, near the South Island. 



You will pay particular attention to trying the current daily, if 

 possible ; and when running at night, in order to avoid passing over 

 banks, &c, you will get a cast of the patent lead every hour, about 

 forty fathoms up and down. This may be easily done, sailing at the 

 rate of seven knots. 



Your dip and intensity apparatus will be used at every island you 

 can find at one hundred and fifty miles apart. I wish a series to be 

 carried across this ocean. 



You will pay particular attention to your sailing and keeping toge- 

 ther; and when the weather proves fine, spread so as to cover as much 

 space as possible, keeping two good men on the look-out. 



There are several reefs lying off Gardner's Island, on its north as 

 well as its south side. 



In the vicinity of shoals, or where they are supposed to exist, you 

 will not run at night, taking care not to fall to leeward of their locality. 



Any islands or reefs fallen in with must be carefully surveyed to 

 ascertain the extent of their dangers, and you will ascertain also if they 

 afford any supplies of wood and water, whereat a vessel might recruit. 



Every three days you will get a comparison with the Oregon's 

 chronometers ; and your positions, together with courses, must be repre- 

 sented on your charts. 



After you have reached the locality of the islands of Todos los 

 Santos and that called South Island on the chart of Arrowsmith, you 

 will pass directly into the China seas by Formosa Passage, making the 

 north Bashee, and then proceed direct to Singapore, where you will 

 arrive without fail in the first week of February, and there await me 

 or orders. 



There are many shoals and reefs which it is impossible for me to 

 draw your attention to particularly ; but I desire that you will let no 

 opportunity pass of gaining information relative to every thing that 

 may lay in your route towards the coast of Japan, and that may be 

 useful to our whaling interests. 



Wishing you a pleasant cruise, I am, &c, 



Charles Wilkes, 

 Commanding Exploring Expedition 

 Lieut. Com. C. Ringgold, 



U. S. Brig Porpoise. 



vol. v. 2\] 67 



