51. 
oByi interpolati between two successive moments at which 
the difference from the mean time of the one place is known, 
we can now find the difference from the mean time of that 
place in the same moment in which the difference of the 
Chronometer from the mean time of the other place was as- 
certained yep observation, and thus determine the dif- 
fenengs of longitude between the two places. In this man- 
ner we find by the three A, Rica of which the observa- 
tions ere the following res 
DIFFERENCE OF LONGITUDE. 
* P ‘Tvals|_ Between the two Stations. 
N TIME OF in mean time. |~Arnold 2111. | Morice 201. 
Mr. Thom = 8 a 004 ys. 
ment No. 1, July 28 1.869 
Station nea the Rat et 875 ‘ 2! 20! 59 9! 21! OT 
age, y > a 
Mr. Thompson’s Monu- 2 go ae 
ment No. 1, July 31, 
+ MEAN TIME OF 
Meet Suly.28, 1.329 j 
+; 's Monu- 
1 ee aye te Oe a ee 
ase y 
: ~~ "se poe 
age, Aug. 1 F Piven: : 
Mr. Thompson's ow 004 — ; 
__ment No. 5 : 
Mean ioalk of tin Chronometer, - = ee | ee i | 2 21 64 
Mean of all Resu 
Difference of Longit tude between Mr. Thompson’s Monu- 
ment t and the Station near the Rat Portage, — 2’ 21” 65 
r. Thompson’s Monument No. 1 is not the most north- 
west ‘poun in that vicinity. The bay on which it is placed 
extends about a mile farther, and terminates in a sm 
which is free from rushes, and not fed by any considerable 
brook. Beyond this point, there is a swamp, which no doubt 
is part of the lake in the spring and fall of the year; but I 
have considered as the termination of the lake, in the ote 
west direction, the extreme northwest point of the pond 
which we reached by paddling, without any difficulty, in the 
loaded canoe. 
