168 S. Newcomb— Variability of the Earth's axial rotation. 
that the maxima coincide,—it seems to me that we have the 
whole right to ascribe reality to your remarkable hypothesis on 
the variability of the earth’s axial rotation.” 
On this paper of Mr. Glasenapp I remark that the case does 
not seem to me so well made out as he considers it. The 
one doubtful term of lon riod in Hansen’s tables of the 
moon which I did not take out in making the comparison on 
which the above correction is founded. This term is that 
depending on the longitude of the moon’s node, which Hansen 
ound more than a second larger than Airy and others 
have from observations. I shall, therefore, determine the out- 
standing mean errors in the lunar theory when we take from 
Hansen’s tables; (1) the excess of his secular acceleration over 
theory, 5”’4T? ; (2) the empirical term depending on the action 
of Venus; and (8) the above mentioned excess of his value of 
the 19 year term, assuming it to be 1”. The following table, 
year, | Correction given bY | onctndea|EtTors of Hansen's Theory |Corrections of Barth 
reenwich.| Washington.| Correction a.) 2.) a) 1a te . 
a . a s 
1850 | +03 | —1'3 00 =|+0°05|40-56 | +0°7 | +1°3 |—0-4 |_—0°8 
51 +1°5 +01 +1°3 0°04} 0°45 | +14 | 4+2-8/414/+27 
62 +0°9 aes +0°9 +0°03} 0°36 | +1°5 | +2°3/41°2/+2°3 
56 +10 Saat +10 | 0°00/ 0°09 | +0.3 | +1-4/4+1°5)+2°8 
57 +15 25 +1°5 ----| 0°02 | —O°l | 41°414+1°8 | +3°4 
58 +2°0 +15 +18 ~---| 0°05 | —0°4 | +1:4/4+2:1|+40 
62 +2°4 +2°4 +24 sou. | 0°05 | —1°0 | +.1°4/4+3°3 | +63 
63 +32 +12 +1°7 0. 0 0-8 | +0°9/4+3°1|/4+5°9 
64 +071 —10 —O0°4 +0°01| 0°09 | —0.6 |—0-9/+1°6 | +3°0 
65 —11 —2-4 —1:7 0°01 014 | —O°3 | —1°5 |+1°3/}4+2°5 
66 —2°2 —2°5 —2°4 0-0 0° 0-0 | —2°2}+0°9/+1°7 
67 —3-9 —41 —4'0 0°03 | 0°28 | +0°3 |—3°4; 0°0 0 
68 —44 —4:5 —45 0°0: 0°36 | +0°6 | —3°5 |+0°2 | +0°4 
69 4-6 —5°5 —50 0°04) 0» +0°8 |—3°7 |+0°3 | +0°6 
70 —50 —61 —5°5 0°05; 0°56} +0°9 0/+0°3)+0°6 
1 —70 —7-2 —T1 0°06) 0°67 | +1°0 | —5-4/|—0°8 |—1°5 
—T8 —78 |+0°07|+0°80 | +1°0 9 ( 9 
