348 Capt. Kater's experiments for determining the variation 
Transits observed at Unst. 
Stars. 
July 22. 
July 24 . 
July 25 . 
July 26 . 
July 27. 
July 28 . 
h. m. s. 
h. m. s. 
h. m. s. 
h. m. s. 
h. m. s. 
h. m. s. 
# The Sun 
, 
0.13.59,32 
. • 
0.15.41,63 
0.17.25,41 
Arcturus 
6.14.18,14 
a . Ophiuchi 
. 
• 
9.23.43,56 
. 
9 >I 4 , 3 °» 5 1 
* Ophiuchi 
9.55.36,41 
• 
9.46.18,1 1 
. 
9.37. 4,48 
n Serpentis 
10.18.25,08 
. . . 
10. 9. 6,1 
. . . 
. . . 
9 * 59 * 5 Z »73 
a , Lyrae 
10.37 5 
. 
10.27.44,82 
• 
10. 18.32,1 1 
a . Orionis 
21.50.15,3 
. . . 
• • 
21.34.48,69 
. . . 
From the above data the following rates of the clock were 
obtained, by dividing the difference between the times of the 
transits of each star by the interval in days, and subtracting 
this from 3 m -55 s ,9i, the acceleration of the fixed stars in 24 
hours. To this, which is the rate of the clock in a sidereal 
day, the gain of the clock (o s ,i4) in four minutes was added, 
to obtain the rate for a mean solar day. 
Rate of the clock at Unst. {Gaining.) 
Stars. 
From 
22 to 28. 
From 
22 to 27 . 
From 
22 to 25. 
From 
25 to 28. 
From 
24 10 28. 
From 
24 to 26. 
From 
26 to 28. 
The Sun 
Arcturus 
a Ophiuchi 
v Ophiuchi 
n Serpentis 
a Lyrse 
a Orionis 
50,57 
5°>73 
50,66 
50,57 
50,73 
49 >95 
49-72 
49- 3 2 
5«»7° 
51,41 
5U59 
51,81 
51,10 
0 
0 
52,09 
Mean by the 
Stars' 
50,63 
50,73 
49,66 
51.63 
• • 
• • 
• • 
Mean by the 
Sun. 
• • 
• • 
• • 
• • 
51,10 
0 
0 
52,09 
* To the observations of the sun the equation of time must always be applied, in- 
order to obtain the rate of the clock. 
