DEPARTMENT OF MERIDIAN ASTROMETRY. 



153 



Then began the preparation of copies of the observing record to be sent to 

 Albany. This included the name, the approximate position, and the magni- 

 tude of the star observed, with the concluded mean transit ; in zenith-distance 

 the means of the four microscopes corrected for runs and graduation-error, 

 together with designation of the point in the field where bisection took place. 



This record was finally dispatched to Albany by registered mail, and up 

 to the present writing has reached series 253. It is proposed to continue the 

 dispatch of this record to Albany until the whole of it has been received, 

 before sending the original observing record made at the instrument. As 

 security for the transit record, the forms upon which the transits were re- 

 corded from the chronograph sheets are arriving by registered mail, and the 

 chronograph sheets will accompany the observing books, at the end, as part 

 of the original record. 



In the same way copies of the readings for instrumental record and for the 

 refraction-arguments are sent to Albany in advance, so that when the instru- 

 ment is taken down it will be known that complete copies of the record have 

 been received in Albany as security for the preservation of the result. 



As explained in previous reports, the plan of observing at San Luis (four 

 times each in the minimum) our standard stars situated between — 20° and 

 -f- 49° was adopted in order to get material for constituting a firm connec- 

 tion between the observatories at Albany and San Luis. Corresponding 

 measures are to be taken at Albany. Thus it is expected to determine a con- 

 stant correction to the adopted flexure-correction of the instrument and those 

 values of the refraction constant at each observatory that will best harmonize 

 the results from the two stations. The following statement exhibits the 

 progress made in determining the positions of stars at large north zenith- 

 distance at San Luis : 



While the latitude at San Luis, according to concurrent experience, is too 

 small to permit of a reliable independent determination of the refraction 

 from circumpolar observations alone, it has been thought best to provide a 

 large number of observations below the pole that may serve to strengthen 

 the determination otherwise obtained. For other reasons the observations 

 below pole are very numerous down to 66° of zenith-distance. Beyond that 

 we have : 



