of the Rutherfurd Photographs. 225 



March 25, March 24, March 18, March 22, 



x direct : y direct : x reversed : y reversed : 



60.7692 55-or33 58.7883 64.5497 



7695 0104 7887 5457 



773 r 0100 7870 5448 



7712 0123 7871 5450 



Mean, 60.7708 55-°ii5 58.7878 64.5463 



Taking the differences between these and the corresponding 

 measurements for Star 7, having regard to signs, we get : 



Coordinates, — 14.6976 — 19.0257 — 146946 — 19.0251 



Eotation Cor., o -f- 4 -f- 2 o 



Final Coord., — 14.6976 — 19.0253 — 14.6944 — 19.0251 



These are the quantities given in Table V, which needs no farther 

 explanation. In comparing the direct with the reversed coordin- 

 ates, it should be remembered that unity in the fourth decimal 

 place corresponds to about o."oc>5 of arc of a great circle. 



