[ 36i ] 
lefcopes; and Mr. Edward Nairne, whofe (kill like- 
wife in the. fame way, and in making all kinds of 
mathematical and philofophical inftruments are fuf- 
ficiently known to the public. 
Mr. Elorfley and Mr. Dunn obferyed with me in 
the great room ; Mr. Elitchins and Mr, Hirft in the 
eaftern fummer-houfe ; and Mr. Dollond and Mr* 
Nairne in the weftern fummer-houfe ; by three 
clocks placed in the refpe&ive rooms, which were 
compared with the clock in the tranfit room, before 
the external contadf, and again after the internal 
contadt was pad ; whence the times of the obferva- 
tions, as noted by the clocks, were reduced to the 
time of the tranfit clock, and thence to apparent 
time. 
Their obfervations, together with my own, are 
given in the following table, as reduced to apparent 
time. 
External 
contact. 
Regularcir- 
cumferences 
in contadt. 
Thread of 
light com- 
pleated, or 
the internal 
contaft. 
Telefcope made ufe of. 
Mag- 
nifying 
power. 
h > " 
h / " 
h / " 
N. Mafkelyne 
7 10 5 8 
7 28 31 
7 29 23 
2 feet reflecftor. 
I40 
M. Hitchins 
7 54 
7 28 47 
7 28 57 
6 f. reflector. 
90 
W. Hi i ft 
7 ii ii 
— 
7 29 18 
2 f. reflector. 
55 
J. Horfley 
7 io 44 
7 28 15 
7 29 28 
1 of. achromatic. 
50 
S. Dunn 
1 10 37 
7 29 28 
7 29 48 
3I f. achromatic. 
140 
P. Dollond 
7 11 l 9 
— — — 
7 29 20 
3I f. achromatic. 
* 5 ° 
E. Nftrne 
7 ii 30 
_ — — 
7 29 20 
2 f. refle&or. 
120 
Mr. Dollond and Mr. Nairne ufed telefcopes of 
their own conftrudtion ; but they did not wait till the 
Vol. LVIII. A a a thread 
