The distance from Lillyhoe to Kinsworth, as found in a former triangle, is 47278,1 feet, and by the last 47280 feet; therefore, 47279,3 may be taken for the true distance in feet. And this triangle, with that preceding it, gives the mean distance between Lillyhoe and Lidlington 49026,1 feet; and, with the triangle Lillyhoe, Kinsworth, and Bow Brickhill, it assigns 69868 feet for the mean distance between Lillyhoe and Bow Brickhill. Distance from White Horse Hill to Shotover Hill 108050,2 feet. 102608 29668,8 And, because the Observatory of his Grace the Duke of MARLBOROUGH, at Blenheim, together with that at Oxford, have been observed with the same care and attention as the principal stations, and also because precise determinations of the situations are of great importance, I shall here insert the triangles formed by their intersections. K ART. XIV. Triangles for connecting the Series carried on from Scutchamfly Barrow and White Horse Hill, in Berkshire, into Buckinghamshire and Bedfordshire, with the Series carried on for the Survey of Essex. The angle at St. Ann's Hill, between the station on Hanger Hill Tower and Hampton Poor House, inferred from General Roy's Account, is 25° 33′ 58′′,5. In 1793, the angle between the staff on Pen Church Tower and Hampton Poor House was taken, and found = 95° 57′ 34′′,5; therefore, the angle between Pen Tower and Hanger Hill is 70° 23' 36". The distance from St. Ann's Hill to Pen is determined by the following triangle, in which the distance between St. Ann's Hill and Bagshot Heath, viz. 46955,3 feet, (see Phil. Trans. for 1795, p. 496,) is used for the base. The distance from St. Ann's Hill to Hanger Hill Tower is 68895,8 feet: this is derived from the mean length of the base on Hounslow Heath. This side, together with St. Ann's Hill and Pen, using the included angle at St. Ann's Hill, as found above, give 94640,5 feet, for the distance between Pen and Hanger Hill Towers. The angle at St. Ann's Hill, between Bagshot Heath and Hanger Hill Tower, is 151° 7' 24",25: this, with the sides Bagshot Heath and St. Ann's, St. Ann's and Hanger Hill, give 17° 13′ 48", for the angle at Bagshot Heath, between Hanger Hill Tower and St. Ann's Hill: hence we have the following triangle. Which triangle gives 37431 feet, for the distance between Stanmore and Hanger Hill Tower. The angle at the station on Bow Brickhill, (see the preceding article,) between Wendover and Kinsworth, is 46° 18′ 8′′,5; and the distances from it to these stations are 92402,2 feet, and 57668 feet respectively: these give the following triangle. Bow Brickhill Wendover 46° 18′ 8′′,5 38 25 21,25 95 16 30,25 From which the distance between Wendover and Kinsworth is found = 67090,7 feet. The observed angle at Wendover, between Bow Brickhill and Stanmore, is 102° 22' 29"; from which, subtracting 38° 25′ 21′′,25, the angle between Bow Brickhill and Kinsworth, we get 63° 57' 7",75, for the angle between Kinsworth and Stanmore. Again, the observed angle at Kinsworth, between Bow Brickhill and Stanmore, is 173° 37′ 44′′; from which, subtracting the angle between Bow Brickhill and Wendover, we get 78° 21′ 13′′,75, for the angle between Stanmore and Wendover. If these computed angles are actually such as might be observed, were Kinsworth and Wendover visible from each other, the angle at Stanmore between those stations ought to be 37° 41′ 39′′, nearly: but the observed angle was 37° 41′ 41′′,75; which is so nearly the computed one, as to leave little doubt of the accuracy of those data from which the angles are derived. The distance from Wendover to Kinsworth is 67090,7 feet. |