( 3 ) 
mate a, readily embraced it-, and in framing the Parts 
of the Clock, carefully contrived, that its Pendulum 
might at pleafure be reduced to the fame Length, 
whenever there Ihouid be occafion to remove the 
Clock from one Place, and let it up in another. 
This Clock being chiefly defigned for Aftronomical 
Obfervations, had no finking Part, and its Pendu- 
lum was adjufted to fuch a. Length, that in London 
it vibrated Seconds, of Siderial, and not of Solar 
Time. When it was finilhed, Mr. Graham fix’d it 
up in a Room fituated backward from the Street, and 
on the Northfide of his Houfe, to prevent its being 
diflurbed by Coaches, or other Carriages that paflea 
thro' the Street, and that it might be as little effe&ed 
by the Sun as poffible. Having fet it going, he com. 
pared it with theTranfits of the Star Lucida Aquil# 
over the Meridian, which pafled 
th h. / , t/ 
ao at 8 59 1 5 "I 
.12 at 8 59 1 8 I 
. a 13 at 8 59 2ot I 
u&iftt Z f. at g zz | by the Clock. 
2,8 at 8 59 251 
at 8 59 2 6 
30 at 8 59 27 * 
Hence it appears, that the Clock gain’d twelve Se- 
conds in ten Apparent Revolutions of the Star. 
In order to eftimate how much the Pendulum may 
be lengthened by greater Degrees of Heat, or how 
much flower the Clock would go on that Account, 
when 
