in the length of the pendulum vibrating seconds. 389 
The spot where the above observations were taken, was 
that selected by M. BroT, the distance from which to the 
clock, measured on the meridian northward, was 182 feet 
= 1 "79- 
Adding this to the observed latitude, we have 6o°.45 / .28",2 
for the latitude of the station where the experiments with the 
pendulum were made. 
The latitude of the spot where M. Biot’s apparatus was 
fixed, and which was on the same parallel with mine, was 
determined by Lieut. Col. Mudge, by connecting it with his 
station on the island of Balta, where the zenith sector was 
erected, to be 6o° .45' .29" ,6. But this latitude is dependent 
on that of Greenwich, which was taken at 51 0 . 28'. 40". By 
the observations however of the present Astronomer Royal, 
and the use of the French refractions, which are very nearly 
the same as those of Dr. Brinkley, the latitude of Greenwich 
appears to be 5i o .28'.38",0i, or T',99 less than by former 
observations. This quantity being subtracted from Col. 
Mudge’s determination, we have 6o°.^f.2y ,, ,6i for the lati- 
tude of the pendulum at Unst, deduced from the Trigonome- 
trical Survey, and 6o%45'.28",2 by one series of zenith dis- 
tances of the sun, taken with the repeating circle. 
Latitude of Portsoy. 
The following series of zenith distances of the sun’s upper 
limb, was taken at the bottom of Mr. Watson’s garden. 
