594 



The Account of a 



No. of 



triangles 



Names of stations. 



Observed 

 angles. 



Diff. 



Spheri- 

 cal 



Error. 



Angles corrected 

 for calculation 



Distance!. 



XIX. 



Moor Lynch 

 Mendip Hills 

 Ash Beacon 



54 3 22,5 

 69 26 48,25 

 56 29 51,5 



—0,42 

 -0,49 

 —0,42 



54 3 22 

 69 26 47 

 56 29 51 



180 



2,25 



i>33 



+0,92 



Ash Be,co n fro m { M- Ly^ch 



Feet. 



88571 



76851 



XX. 



Mendip Hills 

 Ash Beacon 

 Bradley Knoll 



58 16 22 



50 8 45,5 

 7 1 34 55 



180 o 2,5 



.0,30 

 .0,28 

 -0,36 



°>95 +1-55 



58 16 21,5 



50 8 45,25 

 7 1 34 54^5 



Bradley Knoll fa-fJjgftS* 



61963,5 

 68653,6 



The distance from Bradley Knoll to the station on Mendip Hills, 

 and also to that on Ash Beacon, is given in the preceding triangles, 

 independent of the above values. The first is 61961,1, and the second 

 68650,6 feet : these distances have their origin in the base on 

 Salisbury Plain. The other distances are 61963,5, and 68653,6 feet; 

 and these depend on the base of verification on King's Sedgemoor. 

 There is, therefore, a difference of 2 t 4 q feet between the values of 

 one distance, (12 miles nearly,) and 3 feet between those of the 

 other, which is about 13 miles in length. If the computations had 

 been carried on from one base to another, the difference between the 

 measured base on Sedgemoor and the computed base, would have 

 appeared to be one foot nearly. I have already delivered it as my 

 opinion, that an error of nine inches may exist in the new base : 

 therefore, these results must be considered as satisfactory enough. 

 A different correction of the observed angles, or another selection of 



