A. Hall— Variations of Latitude. : 223 
Art. XXVIII.— Variations of Latitude ; by AsapH HALL. 
made with the best prime vertical transit instruments oO 
latitude is small. It being thought best to confine the obser- 
Yalons to established observatories, in order that similar series 
j more certainly made in the future, Mr. Fergola has 
“ected the following stations: 
Ca Stations selected. Diff. Lat. a: sire 
Pe of Good Hope—Sydney .--------- 4’ 22” gt 51™ 
hinge —Windsor (Aust) .::-----.- 947 9 14 
Be ago ee ee 3 53 6 40 
Laps New York (Columbia Coll.)-:-- 6 22 5 58 
. °n— Washington ee ie sae 1: 7 4 31 
oy Such stations as these the stars that pass near the zenith, 
Which are best suited for determinations of latitude, can 
observed at both stations at nearly the same zenith distance. 
~The conditions would be such that the variations of refraction 
e 
te b small; and if the observations are made with care 
th skill, and with the best appliances of modern astronomy, 
tis difference of latitude of the two stations must be — 
pe With the utmost accuracy. If the observations should 
ti "epeated after an interval of fifty years or more, the ques- 
Sree, the variability of latitudes would be subjected to a 
ere test ; 
The Conf : ‘uesti hich was once 
/onference has raised an old question waic’ 
Ps discussed among astronomers. Two centuries ago the 
hee that latitudes vary during the year was a common ook 
the Progress of astronomy, and the complete reduction 
