524 APPENDIX. 



now attached to the brig will leave no excuse why it should not be 

 done, and it will be expected by me that this part of your duty will 

 meet with the greatest attention. 



Variation will be often taken ; also your dip and intensity observa- 

 tions should be frequently repeated. 



You will endeavour to obtain all the information that may lay in 

 your power, relative to the geological formation, and capabilities of 

 the soil for agriculture, near and about the parts surveyed, also all 

 minerals. The east sides of Quadra's and Vancouver's Islands are 

 known to contain coal, which the Indians get from the surface. It 

 would be desirable to view the locality and get specimens, &c. All 

 water-courses and brooks that may afford water for shipping, will be 

 particularly noticed. 



You will also pay great attention to the tides, their height and fall ; 

 set of currents, and the time of high and low water at full and change: 

 this may be done in a few hours, by marking a staff, stuck in the water 

 a few feet from shore, and an hour or two before high and low water, 

 noting the time by the watch at the same time, and again when the 

 water rises to the same point : the mean will give you the high and 

 low water on that day, which, applied to the age of the moon, will 

 give it on full and change. 



I am desirous, also, that your dredge should be much used at all 

 anchorages : there are many times when it can be done very success- 

 fully in deep water, and the results would be more rare and valuable. 



As respects your astronomical observations, those by the north star 

 I should much prefer to the sun for your latitude, and the time by a 

 star I consider fully as good as by the sun ; and, after a little prac- 

 tice, observations on stars with the artificial horizon will be found 

 easy and convenient, interfering but little with your surveying duties 

 during the day. The accuracy of the survey depends so much on 

 these observations, that a few hours taken from sleep will be amply 

 repaid. 



Let all your work on paper bear date, scale, and name. The names 

 of the Indian tribes, numbers, and extent of the districts belonging 

 to them, it is desirable to get; all curiosities, &c, you will of course 

 preserve. 



Referring you to my General Order of May 1st, and wishing you 

 success in the execution of these instructions, 



I am, &c. 



Charles Wilkes, 



Lieut. Com. C. Ringgold, Commanding Exploring Expedition. 



U. S. Brig Porpoise. 



