THERMOMETRICAL OBSERVATIONS. 30J 



From which it follows, that an arc cf a great circle making an angle 

 with the meridian at the month of Flint river from the fouth, towards die 

 eaft of 87" 17' 22", being the fupplemcnt of the angle EDF, will ftrike 

 tlie termination of the line fuppofed to be drawn frcim B ; provided the 

 diftance be as before Hated. But if the dillance between the points, ihould 

 either exceed the diftance dediiced from tlie previous operations feven miles, 

 or fall rtiort of it an equal number, the line will neverthelefs pafs widiiu 

 half a mile of tlie termination of tlie fuppofed hne, and therefore fall with- 

 in the fpace of uncertainty- as to the real fource of the river. 



If a common furveying compafs fliould be ufed, the before mentioned 

 angle of 87" 17' 22" mufl be diminHhed at the rate of about i' 32" for 

 every three miles, to compenfate for the difference of i" 19' 32" betweei* 

 the fupplemental angle already mentioned, and the angle DFE, to pro- 

 duce as near a coincidence as poffible with the arc of a great circle. 



After erecliiig the mound B, we defcended the river, and encamped on 

 the fouth end of Cumberland Ifland,* to prepare the report of our pro- 

 ceedings to both nations, and make our arrangements for leaving the coun- 

 try. At diat encampment the following obfefvations were made. 



1800. 



March 6th. Unloaded the veffel, encamped and fet up 

 the clock. 

 jth. Cloudy and very cold. 

 8th. Stormy with cold rain. 

 9th. Storm continues, 

 loth. Violent wind, and heavy rain. 

 I ith. Cloudy in the morning, ftrong K. wind 

 and fine rain. — Thermometer 49° in the 

 morning, role to 57". 

 1 2th. Clear, — thermometer 47° in the morning, 

 role to 70". 



— Equal attiluJes of the Sun. 



A. M. 8" 53' 50". P. M. i^ 6' 55". 



13th. Thermometer 47° in the morning, rofe to 

 76". 



K r 2 Emerfion 



* The moftfouthem inclination of the United States on the Atlantic ocean. 



