DETERMINATION OF ASTRONOMICAL REFRACTION. 91 



9*4 y- 457*1 x- 0*02820 = 



3*5 - 203*7 + 0*00018 == 



6*3 - 403*5 + 0*01544 = 



12-7 - 907*2 + 0-03442 == 



5-0 - 368*1 + 0*01090 = 



10*6 - 812-9 + 0*02767 == 



To make these equations more nearly homogeneous, put 



and multiply the absolute term by 100. 



Reducing by the method of least squares, the following 

 system will be found, and from which the values of y and 

 v can be determined, hence obtaining the quantities x and 

 Z. 



515*250 if -326*688 v + 68'4315 = 



- 326*688 y + 216*437 v - 54*7312 = 



Remembering that the absolute term was multiplied by 

 100, the following result from the solution. 



Log v = 8*0860357 Log y = 7*8062727 

 v = 0*0122 y = 0*0064 



[p VV ] = 0*0011673923 

 m - u = 8 

 Log p y = 1*3453805 Log p v = 0*9686940 

 Log r, = 7*9110368 

 r v = ± 0*0027 r y == ± 0*0017 

 From equations (6) and (7) we may now find Z and x. 

 Z=52°-5093 = 52° 30' 33" 

 x= 0*000122 

 Log a a = Log a c + 0000122 [S2° 30' 33" - s] 



11. Conclusion. 



During the reductions, it was very noticeable the manner 



in which the observed refractions varied in accordance 



with the computed ones, due to the alteration in the state 



of the atmosphere. If observations of zenith distance of 



