APPENDIX. 



563 



They will particularly embrace the following, viz. : 



1st. The names of tribes of Indians, and their number. 



2d. Manners, customs, modes of living, disposition, &c. 



3d. The sources and courses of rivers and their branches, with 

 their latitude and longitude, and also of lakes, their extent, and 

 whether head waters of rivex'S, or having any outlet. 



4th. Climate, degrees of heat and cold ; if not thermometrically 

 observed, get the time when trees blossom and fruits come in. 



5th. How long the posts or forts have been occupied, state of fur 

 trade in the interior, number of forts established, where, and among 

 what tribes. 



6th. Timber, kinds and qualities, soil, and all other information, 

 together with accounts, tales, and histories of adventures, that you 

 may hear well authenticated. 



You will observe the following instructions relative to your times 

 and modes of observing, viz. : 



You will keep an accurate map of your route, noting on it the lati- 

 tude and longitude of all your stopping-places, from which position 

 you will take the bearings and angles on all distant hills and moun- 

 tains, direction of ranges, courses of rivers, &c. You are provided 

 with a chronometer, sextant, artificial horizon, prismatic compass, 

 barometer, and thermometers. Your means for obtaining observa- 

 tions will be great : I shall therefore expect you to be very particular 

 and untiring in their use, as much of the information derived from 

 them will depend entirely on your own exertions. 



Observations you will obtain daily, if possible, both for latitude 

 and longitude. When the meridian altitude of the sun is not ob- 

 tained, you will have frequent opportunities by the north star. This 

 observation you will find easy after a Uttle practice, by bringing the 

 two reflected images to cover each other, and having your me°an time, 

 any time of night you will be able to obtain your latitude. 



I also wish you to use the stars for getting your time. The obser- 

 vations of two stars east and west, will give you it with great accu- 

 racy. The best mode of observing stars in the artificial horizon is to 

 clamp your index nearly to its altitude, and await its coming, and 

 when they cover, mark the time. Stars nearly east and west of you 

 are to be preferred, altitude about twenty or thirty degrees. 



All your observations must be worked up as soon after they are 

 taken as possible. I enclose you herewith a few azimuth formulas. 



