io Lieutenant Foster's account of 
adjustments finally completed on the ist of June ; the clock 
put in motion, and the apparatus for measuring the arc of 
vibration fixed in its place ; the barometer and thermometer 
were also suspended after the manner described in the ex- 
periments at Greenwich. 
The perfect stability of the point of suspension being of the 
utmost consequence, spirit levels were arranged on the top of 
the pendulum frame and clock case, to indicate any giving 
way in the foundation of their respective supports from the 
effects of thaw, which at this time very generally prevailed ; 
the foundations however remained solid, and the adjustments 
were preserved, during the whole course of these experi- 
ments, which were not commenced to any good purpose 
before the 14th of June, owing to an unfavourable change in 
the weather. This took place on the 7th of June, and was 
such, as rarely to permit a sight of the sun, and not one 
glimpse of the stars during the above interval from the 7th 
to 14th. 
In ascertaining the rate of the clock, 1 was confined to the 
transits of the sun at noon ; of Arcturus and a. Lyras when 
passing south of the zenith. The sun's transit at midnight 
could not be taken, in consequence of the undulations of his 
limb, caused by being too near the top of the high land in 
that direction ; neither could a Lyras be seen soon after noon, 
from the general hazy state of the atmosphere at the eleva- 
tion of 22 degrees. At the time of the sun's transit his rays 
were prevented from touching any part of the instrument, by 
a screen of canvas placed between the object-glass of the 
telescope and the slit in the roof of the house ; it had a small 
hole, through which the observation was made, but being 
