The angle observed from the station on Danbury Steeple, between Hatfield Broad Oak and Thaxted, was 30° 33' 40"; this, with the including sides, 85094 and 101330 feet, gives the following triangle: Again, the angle observed at Danbury, between Thaxted and Stoke was 66° 43' 8"; this, with the sides which form it, Danbury and Thaxted, Danbury and Stoke, gives the following triangle: The angle at Lavenham Steeple, between Stoke and Thaxted, was likewise observed, and found to be 89° 10′ 30′′, which, with the distances of these latter stations from Lavenham, 48039 and 124430 feet, gives The angle at Danbury, between Southweald and Hatfield Broad Oak, was found to be 54° 44′ 30′′. The distances from Danbury to Southweald and Hatfield Broad Oak have been already found, the former being 77622 feet, and the latter 85096 feet; from these we get the triangle, Hatfield Broad Oak 57 33 25, which gives 75104 feet, for the distance between Hatfield Broad Oak and Southweald Steeples. In order to connect the preceding triangles with those carried on for the survey of the south-western part of Essex, and of Hertfordshire, stations were selected on Hampstead Heath, and on Highbeech in Epping Forest, to which the great theodolite was taken, as related in the article detailing the particulars of the operations in 1799. The triangles making this connection are the following. The first, namely, at Severndroog Tower, 28° 58′ 10", and the sides Severndroog Tower and Southweald, Severndroog Tower and Langdon Hill: the first is 73787 feet, and the second 88470 feet. From these data, we obtain the distance between the station on Langdon Hill and that on Southweald Steeple = 43001 feet. Foot of the cross on the dome of St. Paul's from the station on Severndroog Tower 39962*. From the last triangle, we find the distance from Severndroog Tower to the station on Southweald Steeple to be 73795 feet; this, it will be perceived, is deduced from the distance between the cross on the dome of St. Paul's and Severndroog Tower; but 73791 feet has been found by the triangle, which is derived from the distance between the latter station and Wrotham. A difference of 4 feet on such a distance, all things considered, is not a large quantity. As it became necessary to ascertain the situation of a high building near Berkhamstead, which, for distinction sake, I shall style the Gazebo, the instrument was removed from the station on Highbeech, to another farther west of it, as some trees obstructed the view of this object from the former. To get the distance from St. Paul's to this new station, the distance between it and the old one was measured, and found = 460 feet: the angles in the following triangle were also observed. At the new station on Highbeech, the angle between the staff on the Gazebo at Berkhamstead and the old station was observed, and found to be 141° 45′ 50′′. This angle, with the measured distance between the stations, and also the distance from the Gazebo to the new station, which are respectively 460 and 49628 feet, gives 49987 feet, for the distance between the new station on Highbeech and Berkhamstead Gazebo. The angle between Albury and Elmdon Steeples was observed, at Henham on the Mount, and found to be 72° 47′ 38′′. The distances from the former stations to the latter are 37882 and 45275 feet, which give the following triangle: The angle at Henham on the Mount, between Hatfield Broad Oak and Thaxted Steeples, is 109° 10′ 44′′; and the distances of the latter stations from the former one are 39266 and 22988 feet; from these data we have the triangle, 64 26 Hatfield Broad Oak 24 52 47, which gives 51608 feet for the distance of Thaxted from Hatfield Broad Oak. Hatfield Broad Oak 1950 High Easter 24858 21460 |