in order to afcertain the height of Mountains. 551 
Mr. de s aussurEj. at 4 feet -v 
below the fummit of the ? 
Mole, — J 
Mr. de saussure’s barom. 
ftands higher than Mr. de ? 
luc’s ordinarily by, J 
Thermometer attached + i°. 
Mr. de lug, 78 feet above \ 
the lake, — ■ i 
Therm, attahced 4-6°, — 
Difference of the Log. 
In. 
L. 
i6ths. 
22 
8 
0 
+ 
Heat' of the air. 
— 
Of 
1 6ths of a line. 
Log. 
6387587 
f T 
REAUM. DE LUC’S 
Therm. Therm. 
+ 10 —15! 
22 
8 
o| =435*4 
27 
0 
O 
— 
6 
26 
11 
10 
7141620 
+ 15 — 4 
ig°| x 2JJAA2 zz the corre£lion for the temperature, 
Corre£l height in French toifes, — • 
754 ‘°33 Sum — T 9f 
-14.854 
739^79 
x 6 
Height in French feet, — *— 4435-°74 
Mr. de luc’s barometer above the lake of Geneva, 4-78. 
Mr. de saussure’s barometer below the fummit of \ 
the Mole, — — — j -r 4* 
And confequently, the fummit of the Mole above \ 
the lake, in French feet, — • — J^-> 7 ° 
Which reduced to Englifh feet is, — — 4814 
But, by a mean of my trigonometrical operations, ^ 
this height is ( vide chart) — ■ — 
] 4 8 8 3 . 
Difference, or error of the barometrical rules. 
—69. zz 
To 00* 
This laft obfervation ferves at leaft to fhew, that the 
error I am contending for is on the defective fide, though 
it gives the quantity of it fomewhat lefs, but by no means 
deferves that confidence which the other companions do; 
for, befides that this fingle obfervation may be concluded 
lets 
