experiments made with an invariable pendulum , &c. 325 
P. S. I may here take the opportunity of correcting an 
error in the “ Account of Experiments for determining the 
variation in the length of the Pendulum vibrating seconds at 
the principal stations of the Trigonometrical Survey of Great 
Britain/’ 
In the first series of observations made with the repeating 
circle for the latitude of Clifton, P41 ",6 has been applied as 
the correction for the level instead of 141 ", 6 = s' 21", 6 . 
The resulting latitude, when the proper correction is made 
is 53 ° 27' 44", 94 instead of 53 ° 27' 40", 94, and the greatest 
difference between the five independent latitudes of Clifton 
3", 48 instead of 5", 24. 
