_ 
: 
A. Hall— Variations of Latitude. 225 
Observer, Date. Latitude, 
2 ae 1843 + 59° 46’ 18’°73 + 07013 
Oviden-:... 1866 18 ‘65 + 0 014 
een 1872 18 ‘50 + 0 014 
ro these are absolute determinations of latitude, that three 
‘ifferent observers took part in the work, and that the varia- 
tion from Peters to N yrén is only 0”-23. An astronomer of 
“perience would be cautious, I think, in ascribing this differ- 
“nee to an actual change of latitude. But the evidence in this 
' tistie, the present Astronomer Royal of price gives 
aig the observations of the years 1836 to 1879 t 
des of the latitude: 
1836—1849 Latitude — 51° 28’ 38°15 
1851—1865 Latitude 38 ‘13 
1866—1879 Latitude 38 °17 
nites results give no evidence of a secular change of lati- 
- 3 Again, a determination of the latitude of Washington, 
883, gives 
Latitude = 38° 53’ 38-94, 
Th. this result also furnishes no proof of a change of latitude. 
Pulke Negative results show that in the case of the latitude of 
tis ibe we must wait for further proof before assuming a rea 
War change in the latitude of that Observatory. 
°0 far as periodical changes of latitude are concerned, there 
ig : : 
-4 theoretical reason why such changes might occur. our 
and it the origin of things received its motion around the sun 
dite 't$ motion of rotation on an axis from a single impulse, the 
the Ction of the impulse would pass about twenty miles from 
tha earth’s center, and it would seem to be but little probable 
ne the earth would begin to rotate around one of its principal 
ut the observed constancy of latitudes shows To. 
“teh was Very nearly the case, or that some cause has 
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