PHOTOGRAPHIC RESEARCHES NEAR THE POLE OF THE HEAVENS 



71 





Observed Differences, 

 Harpham — Peirce. 





Star. 



Angle. 



1 



-Hf. 83 



2 



..51 



3 



.49 



4 



.70 



5 



.74 



6 



.63 



7 



.61 



8 



.90 



9 



.55 



10 



1.34 



Mean. 



.68 



0*55 



It follows from 



table that the probable error of a final 



dinate, depending on the means of the measures of Miss Ha 



and Miss 



Peirce, is: 



0'.'22 for the right ascensions, 

 OTl 5 for the polar distances. 



Another solution was therefore made, giving half weight to the equat 



derived from the rij 

 unknowns d\ and dr k 



This solution eave for the values of 



« = 



0?68 



0'.'057, 



dt\ 



o:i5 



V 



0:057. 



These numbers agree so closely with the results of the other solution, 

 that the values of A n A' and A n co will not be changed materially. The resi- 

 duals will also remain practically unchanged in the new solution. The prob- 

 able errors of d\ and dr\ are, however, reduced as shown above, and the 



probable error of one equation of unit weight is now only 



0?34. The 



following are the sums of the squares of the residuals, after weighting the 

 right ascensions 7a, and assuming, as we may, that the residuals are not 

 changed numerically in the new solution. 



[pvv] 

 [pvv] 

 [pvv] 



17.86, for the right ascensions, 

 10.37, for the polar distances, 

 28.23, for all together. 



A solution on the supposition that the telescope moved was next at- 

 tempted. For this purpose, the following equations of the form (17) were 

 computed, the coefficients of A n A' and A n w being multiplied by 0.01. 



$23.-M*T. CTp. 71 



3* 



