S. Newcomb— Variability of the Earth's axial rotation. 169 
ished b 
The ‘ference between the numbers in the last column and 
those formerly cited arises almost entirely from the change of 
1” in the value of Hansen’s nineteen-year coefficient. Let us 
now treat Mr. Glasenapp’s residuals by a method intermediate 
between the two which he adopts. I have divi is re- 
siduals into ten groups, and in order to make the observations 
of ingress and egress comparable, have corrected them as fol- 
WS: 
The ingress residuals by —15*2+-0°08 (¢—1861°0) 
The egress residuals by +13°4 +0°25 (¢—1861°0) 
and have then taken the mean by weights of each group. The 
results are as follows: 
Excess of Theory over observation. 
Ingress. Egress. Combined. 
Pepieecer oe a a 
Date. | c—o. | we. | Date. | G-0: | We | Dete. linocrrect’al Corrected. | *™ 
8. 
1849-0 |— 9:4| 8 |1g48-8 |+ 01| 16 |18489| —31 —21 | 24 
50°7 |— 26] 8 50°3 |— 4:7] 8 05| —3°6 —88 | 16 
62 | + Ga] 8 535° |—392 | 2 53-1] —65 —9-0 
56°3 1+ 90) 7 56-4 |— 6 563| +3°9 +09 | 13 
585 |— 0-4] 30 58°8 |+ 49] 14 58°6| +13 —2T 
61] |+ 67] 8 61°0 |+ 5°7| 13 61:1] +61 +01 | 21 
63-7 |— 11] 16 63-7 |— 5 63°7| —3 —85 | 21 
67°6 |4151] 6 67°38 |— 16 67'8| +2°3 OE Ly aa 
70°5 |— 40] 9 70°7 |— 5°9| 12 10°6| —5°2 ae 21 
72°6 |— 81] 28 72°38 |— 0°6| 48 72°7 3-4 —14 | 76 
The columns C-O show the Finnie @) when the by of 
the day is supposed rhapeaieet (2) when the times are ¢ 
for hypoth ae ‘earth slow” from the last column of the last 
vagal! e. We have now to an which series can be best repre- 
an expression increasing uniformly with the time. 
Siti oe least squares we find the expressions to 
Uncorrected residuals = —0*80— ee 4 
Corrected residuals =— 2°45 -+0°039(t—1860°0). 
ote the value of these —— we find the residuals 
1 outstanding to be as follows 
