OPERATIONS IN THE PENINSULA. 



553 



The Arc comprehended hy the Meridians ^Savendroog 

 and Mullapunnabetta. 



Let S and M be the stations at Saxendroog and 

 Mullapunnabetta, and 

 P the pole, and SR 

 be a great circle per- 

 pendicular to the meri- 

 dian SP at S, and also 

 Ss a parallel of latitude 

 at the same point S. 

 Then we have given the 

 observed angles PSM 

 and PMS, the distance 

 SM, and the latitude of 

 S, to find the latitude 

 ofM. 



In the spheriodical triangle MSR, the angle MSR 

 = PO"* — z. PSM = 0" 2' 14".73, and the angle SMR 

 - 180o— z. PMS = 90" ll' 15".6l, and these being 

 Corrected for the chords, we shall have the angle 

 MSR = 2' 14".73, and the angle RMS = 90 1 1* 

 ]5"..58 for the chord angles. Whence theangle SRM 

 = 180o — sums of the above angles, or 89" 46' 29.69, 

 and with these and the side or chord MS, the dis- 

 tance given by the triangles, we shall find the chord 

 of the perpendicular arc SR = 35/644.6 and the side 

 MR = 233.64 feet, and this last may be taken either 

 as a chord or arc indifferently. 



Now the spherical excess of the triangle SMR is 

 0".02, and the sum of the corrections for the angles 

 MSR and SMR being — 0.03, the difference between 

 this sum and the said spherical excess is + 0.01 the 

 correction for the angle MSR, which applied to the 

 chord angle, we get the angle MRS or PRS as an 

 observed angle, equal 89" 46' Qg'.dS, 



Continue the meridian PS to t, and draw Rt pa- 

 rallel to Ss. Then, since the small angle SRt, or its 

 equal RSs, is half the difference between the angles 



