QAP QUAN ACCOUNT OF THE - 
«99. In leaving off the vu vork in'the evening of each day, it was of the 
first importance, that the point indicating the termination of the day's mea- 
‘surement, should be so marked, as to leave no probability of its being displa- 
céd, and also to allow of the work being resumed readily the following mor- 
Ring, and without error.. These two particulars were I think perfectly an- 
swered by the plummet and tripod already described. ‘Theplummet which 
weighed two pounds, and was .attached to a brass wire, being suspended 
from. a theodolite stand, was set so nearly touching the brass edge of the 
fore rod, as'to leave little more than ’z of an inch, between: the quantity, 
was easily and correctly estimated by means of a scale of equal parts, held 
behind the rod and wire. When the wire was perfectly steady, the nick in 
the ivory piece of the tripod, (well fastened into the ground) was set ex- 
actly to it, the manner of doing which will be readily understood from the 
description already given of it. A cordon of stands united by ropes was 
then placed all round, the rods also being left standing. And a sentry was 
posted, and during the night regularly relieved, to guard the tripod from the 
approach of any animal. The examination in the morning however never 
detected any thing wrong, and therefore on this head I think we may have 
the most perfect confidence. 
f 
93. Dunrina the measurement there occurred one accident, and two 
“omissions, which compelled me to measure twice the distance, in two of the 
‘three cases, from the last passed picket. As I never omitted to notice and 
‘TeGis ster. the quantity, by which any rod overshot or fell short of these 
pickets, they formed a series of fixed points, to which I eould return with 
the greatest confidence, in case of any part of the measurement, beyond 
