328 FIGURE OF THE EARTH. 



inuths, having regard always to the relative convergence of 

 different meridians. 



The author has made observations for determining the lati- 

 tude of the two extremities of his arc, and has also determined 

 the azimuths of the exterior sides in his series of triangles by 

 means of the greatest elongation of the pole star. 



In the calculations that I have m ^e, I began at Clifton in 

 Yorkshire, the northern extremity of the arc, and for this 

 purpose the following are the data furnished by Lieut. Col. 

 Mudge, 

 Col. Mudge'» Latitude of Clifton reduced to the centre of the station 53« 

 27' 36,"62. 



Azimuth of Gringley, seen from Clifton, and reckoned from 

 the north toward the west 256" 17" 25". 



Azimuth of Heathersedge. seen from Clifton, and reckoned 

 in the same direction 118' 8' 8",81. 



from which With these data, and the two tables of spherical triangles 

 the computa- „„ j ^i i • i ft-., . ° 



tions were ^"^ ^"® logarithms of their sides expressed in arcs, the inter- 

 begun, vals between Clifton and the two stations Gringley and Hea- 

 thersedge were found in toises and in seconds of a degree, as 

 well as all the corrections to be made on the first azimuths 

 increased by 180^, as azimuths of Clifton seen on the horizon 

 at these latter places. 



andcontinu- The same process was continued for the following stations 



ed tnrourn the . • n • ^ o - 



whole series. '" succession, all the way to Dunnose in the Isle of Wight, 



which is the southernmost extremity of the series. 



In this manner we have the latitudes and azimuths of each 

 station, by means of two or three preceding stations, and con- 

 sequently we have a verification of all the calculations that have 

 been before made by Lieut. Col. Mudge. 



The results of ray calculations are contained in the two folr 

 owin tables. 



)^TSt 



