302 



THE SAYRE OBSERVATORY. 



These are not included in the above summary. It must not be understood that this pro- 

 cess of exclusion was employed merely as a convenient means of rejecting those deter- 

 minations which gave inconveniently large residuals. On the contrary, the residuals 

 given by the rejected observations were in the majority of cases smaller than those of 

 many which were retained. 



As may be supposed, the accuracy of these earlier observations was far below the 

 standard since attained in this class of work. Their value lies mainly in the fact that 

 they precede by several years the period when the problem of Latitude variation began 

 to attract serious notice, and it may be claimed that they had some influence in directing 

 attention to this important subject. # 



The probable error of a single determination for the various periods was as follows : 





ii 



1870 



0.578 



1877 



.457 



1885-86 



.407 



1888 



.366 



1889-90 



.234 



The values of the latitude for each day of observation follow. These of course 

 depend on the values of the declination employed, no means for adjustment being at 

 hand. In forming the means all have been given equal weight. 



