M.-P.— Vol. I.] CRAWFORD— CONSTANT OF REFRACTION. 



195 



Weighted Observation Equations. 



No. 



a 



n 



To render these more nearly homogeneous, let D = D; 

 ioox=y and multiply the absolute term by 100. Then we 

 have the following 



Weighted Homogeneous Observation Equations. 



n 



Combining these by the method of Least Squares we 

 obtain the following 



Normal Equations. 

 + 341.28 D— 254. 512 y= —61.7188 

 — 254-5 1 + I 97- I 5 I = +53-43 8 3 



Solving these, remembering that the absolute terms had 

 been multiplied by 100, we have 



log 0=7.75694; log y=8. 00376 or log x=6. 00376. 



Now since D=Zx, we have log Z = i. 75318, 



Whence x= +0.0001009 and Z=56°.647 = 56°38'49". 



Substituting the values of D and x, thus found, in the 

 Weighted Observation Equations, we find \_pw~] = 



