...chainlengths being insured with the most minute precision ; while at the same time the greatest care was taken to secure correct alignment, to adjust differences...brass cup sunk in the ground and filled with water. It was carefully fenced round for security, and a military watch took charge of it by night, or till...

...chain-lengths being ensured with the most minute precision ; while at the same time the greatest care was taken to secure correct alignment, to adjust differences...brass cup sunk in the ground and filled with water. It was carefully fenced round for security, and a military watch took charge of it by night, or till...

...till night in the field." Where each day's work left off a plumb line was suspended to mark the point; the plummet vibrating in a brass cup sunk in the ground and filled with water. The spot was carefully fenced round and guarded during the night by a military watch. The next two...

...night in the field." Where each day's work left off a plumb line was suspended to mark the point ; the plummet vibrating in a brass cup sunk in the ground and filled with water. The spot was carefully fenced round and guarded during the night by a military watch. The next two...

...reduction to MSL (described later on) was then used Reduction to /- »1 /- .> 1 • r , *or t"e "rst t1me 1n the h1story of geodesy. The greatest care was taken...In 1791, when the work of the Ordnance Survey was resumed, it was decided to re-measure this base with a steel chain. Two chains of 100 feet in length...

...This reduction to MSL (described later on) was then used Seduction to for th(j first time ^ ^ hUtory of geodesy The greatest care was taken during each...In 1791, when the work of the Ordnance Survey was resumed, it was decided to re-measure this base with a steel chain. Two chains of 100 feet in length...