[ 47 ] 
IX. Obfervations of the franft of Mercury, May 4, 1786, at 
Drefden. By M. Kohler, Infpedlor of the Mathematical 
Repofitory of the Klettor of Saxony ; communicated by the 
Count de Bruhl, F. R. S. 
Read December 21, 1786, 
Apparent time. 
/ // 
9 21 54 beginning of the planet’s egrefs, doubtfuL 
9 25 23 complete egrefs, or lall contact, very certain. 
The telefcope with which Mr. Kohler obferved, was a 
9-feet refractor of Dollond’s, magnifying 104 times. 
He has made a companion of his obfervation with that of 
Alexander Aubert, Efq. from which he has inferred the 
longitude of Drelden in the following manner. 
Mean time. 
U 
Exterior conta£l obferved by Mr. Aubert at 
u. , 
8 27 
Ji 
5 
Equation ... 
+ 3 
28,3 
Difference of parallax 
-f- O 
i 3>4 
Apparent time at Loam-pit Hill 
8 30 
46,7 
Loam-pit Hill well of Greenwich 
4- O 
5* 4 
Apparent time at Greenwich 
O 
cn 
00 
5 2 * 1 
Apparent time at Drefden 
9 2 5 
23,0 
Longitude of Drefden eall of Greenwich 
54 
3°>9 
