S. Newcomb— Variability of the Earth's axial rotation. 167 
the corrections of Damoiseau’s tables, you can easily see that 
very few observations are made during many years, and during 
some not at all. 
‘By means of the quantities (8) we calculate the following 
corrections of the tables for the same epochs, for which you 
obtain the corrections (1): 
1850°5 +) 
55°5 434 
60°5 4.374 
62°5 , +3°9 
64:5 +454 (9) 
665 45°5 
68°5 +6°8 
70°5 +8:2 
72°5 +9:9 
And if the corrections of the tables may be considered as 
constant quantities, the values (9) with opposite signs will be 
the corrections of noon plus any constant quantity; thus when 
we change the signs in the quantities (9) and add to each of 
them the constant +7#9, so that at 1872 the correction of 
noon shall be the same as you have found (1), we obtain the 
following values for the correction of noon. 
Correction of noon. Correction by S. Newcomb. 
3" 
18505 + 
555 2 4-4 aS 
605 +5 +10 
625 +4 +11 
645 +3 +10 
665 +2 + 6 
685 +1 2 
70°5 0 0 
725 =¥ an 
““The comparison of these series shows: : 
1. That the change of the corrections is similar in both series. 
2. That the periods are very near each other. 
3. That the maxima coincide. f . 
“ Although the corrections themselves, in both series, differ 
much from each other, so that they alone cannot give us the 
right to make any conclusion on their reality, but as the disap- 
pearances of the first satellite, as the reappearances (a) give 
the corrections (g) is similar in both series, (c) that the peri 
of these changes are very near the same, in both cases, an 
