ARTICLE III. 



RESULTS OF OBSERVATION WITH THE ZENITH TELESCOPE OK TEE SAY UK 

 OBSERVATORY PROM JANUARY 19, 1894, TO AUGUST 19, 1895. 



HY CHARLES L. DOOLITTLE. 



Read October 19, 1900. 



Introduction. 



The Sayre Observatory, situated at South Bethlehem, Pennsylvania, owes its exist- 

 ence to the liberality of Robert II. Sayre, at whose expense it was erected and equipped 

 in 1868. The object was primarily that of supplying facilities for the instruction of 

 students of the Lehigh University in practical Astronomy. One of the first tasks under- 

 taken by the author of this paper upon taking charge of the department of Astronomy 

 at that institution in 1875 was a very carefu] determination of the latitude. 



The question of possible variations was one of those; had in mind at that time. It 

 was then supposed that it' anything of this kind took place of sufficient magnitude to be 

 measurable, the changes would be secular in character, and that later determinations 

 might furnish valuable data, for deciding the question whether or not such changes 

 existed. Tins first determination was not finally completed until 1878. 



A re-determination was made in 1885 86, which indicated a change of about 0". 4, 

 though the reality of this change was at that time naturally an object of much skepticism. 



The work was resumed in L 888, and was continued with souk; interruptions until the 

 summer of 1895, when my connection with the Lehigh University terminated. The pres- 

 ent paper deals with the results obtained from January 19, L894, to August ID, L895. 

 Although this is a, continuation of work done; during previous years, the methods pursued 

 were such as to make I his in so far an independent series that it may very properly be 

 presented separately. Moreover, as a re-discussion of the earlier observations and their 

 publication in full constitutes a part of the general plan, they will call for no further con- 

 sideration here. 



The final preparation of this material for publication has been delayed by the circum- 

 stance that a, preliminary reduction showed it to be very desirable that the star declina- 

 tions should be determined with a high degree of accuracy and carefully reduced to a, 



