S. Newcomb— Variability of the Earth’s axial rotation. 165 
tions (1) the observations of the eclipses of Jupiter’s first satel- 
lite are represented somewhat better than the uncorrected 
tions may be real, and that your pees on the variability 
of the earth’s axial rotation may rue. 
2. Second Re a 8 
“The second way I choose for the decision of the same ques- 
tion is to determine the corrections of the calintion! tables of 
the first satellite for different epochs, and to deduce hese 
corrections the corresponding ones of mean noon er the same 
“The values of i. and x, z, (8), which were 
deduced from the ohasrttiins rere the quantities (1) give 
the following corrections of Damoiseau’s tables 
(1.) Correction of the tabular mean longi- 
ude of Jupiter’s first satellite... =—27°74°8 
(2.) Correction of the tabular Ce 
of the coliple. 0-0). + <5 ee = —49°144°8 
(3.) Correction of Dela mbre’s velocity 
ight (of the quantity of 4053)... Shp 644-102 
(4.) Value o z, which is negative for dis- 
appe es of the satellite, and pos- 
itive for “his reappearance, . --- ----- ==1°*7384-2°°07 
and with these values we correct the moments of eclipses as 
given in the Nautical Almanac (Damoiseau’ s tables) and ealcu- 
late the quantities (C—O)—that is: calculation—observation 
—for each eclipse observed since 184 
“From these se quantities we derive. the following corrections 
of Damoiseau’s ssa tables of the first satellite. 
a. Eclipse disappeari b. Eclipse reappearing. 
Co est C—O Weight. 
1848°86 + 69 47 184824 —167 77 
922 + 67 3°4 49°27 — 45 8°5 
50°00 +422°7 2°4 50°32 —15°4 76 
51°10 9°2 5°3 53°50 —30°7 ee 
52°70 +22°2 1°6 55°70 —17°2 7 Ae 
55°50 = -+33°2 2°0 56°97 —11°5 vies 
56°58 +20°9 4°7 58°10 —12°2 4°5 
57°72 +163 23-7 5915: — 5°9 7 
58°82 +11°5 v4 60°21 — 63 81 
59°90 +22°9 2°0 61°30 + 4°4 0-9 
61°22 +145 33 62°32 —127 4:4 
62°17 +29°0 2°9 63°37. —283 36 
63°15 +220 3°5 6460 —115 16 
64°28 i! 75 65°70 ~—27°8 O-7 
66-45 +22°6 1°8 66-72 —18°8 3 : 
6763 +33°9 26 67°82 —16°9 
