390 EF. 8. Holden—Measures of the Rings of Saturn. 
I have made some measures of this system which are inter- 
esting in this connection, and which I shall give here althoug 
the series is not finished. They all relate to the position of the 
dusky ring C; and the position of the points / and 7 is invaria- 
bly referred to (the middle of) the principal division, that is, to 
the points ¢ and /. e observations were made in 1879 and 
1880 with the 26-inch equatorial at Washington, and in 1881 
and 1882 with the 15-inch equatorial here. 
| 
| 
ek, {Sis 58. "5. | Mpa a MSs. 
ab SOR Soe | sSaere ae 
ac 2-60 2°329 | 2°622 [3°00] 
ae 6°96 6863 | 5°806 6:97 
af 9°31 8892 : 9°8 
an 40°47 Bt Sh 39°471 40:47 ‘ 
11°58 11°03 11°10 pe Es 
ce (width) 0°47 cea E soos 
ce 4°36 4°534 37184 [3-97] 
of 6°71 6°563 ee 6°88 
ct 28°57 28777 ae [28-05] 
el 35°28 35°339 34°227 Rites 
ef 2°35§ 27029 Ae 2-91 
eg 4-62 4°166 5-292 5 
ej 26°56 26°271 27°859 26°32 
fa 2-27 2°14 “oe 
fi 21-86 22-214 aus 2117 
28°57 28°777 pote 27°58 
gh 17°32 17:940 17-27 17-451 
hi 2 2°14 one ft 
4166 5292 4°42 
hn 11°58 11°03 11°10 ao 
i 2°35 2029 cee 2-24 
il 671 6563 gt 642 
in 9-31 8°892 reared 9°42 
jk aaek 
jl 4°36 4534 3°184 418 
jn 6°96 6863 5-806 7-18 
1 (width) 0-47 x . 
2°60 2°329 2°622 3°00 
mn ooh os Pye ee 
Polar diam. 15°46 see 15°392 16021 
These instruments are provided only with filar micrometers 
and are therefore not suitable for measuring diameters and dis- 
reas uch as occur in Saturn. This work properly belongs 
2 heliometer and the main part of it will undoubtedly 
n be done at the Strassburg gout wings But no alias: 
oe now built has light enough to deal effectively with the 
dusky ring, and I therefore confined my measures with the 
Washington equatorial to that ring. The measures were referred 
