j periodical V ariation in Algol. 48 r 
clap fed between the federal obfervations ; the third exhibits the 
quotient a riling from a divifion of thefe intervals by a certain 
number of revolutions, each of two days and twenty-one 
hours, which number of revolutions are exprefled in the lad 
column. 
’['tie day and time when 
Algol was obferved at or 
near its lead: brightnefs. 
The different in- 
tervals between 
the fevcral ob- 
fervations. 
The quotients or 
thedivifionsqfthe 
2(1 column by the 
4th. 
A umber 
of revolu- 
tions. 
d. 
1782 Nov. 12 
J 3 £ 
CO 
d. 
h. ' 
d. 
h. 
16 
Dec. 28 
d 
45 
2 1 
2 
20,8 
1783/30. 14 
J z 
9? 
17 
3 v 
2 
20,6 
6 
3 1 
Hr 
n 
5 
2 
20,8 
6 
Feb. 6 
8 
5 
* 7 + 
2 
21, 
2 ■ 
23 
12 + 
17 
4 
2 
20,6 
6 
26 
9 1 
2 
2J| 
2 
21,5 
t 1 
Mar. 2 1 
8f 
22 
23 
2 
20,9 
8 
April 10 
10 + 
20 
2 
20,8 
7 
April 13 
8 
2 
22 
2 
22,* 
i 
May 3 
9 ? 
20 
1 
2 
20,7 
7 
The refults in the third column agree fo nearly, that there 
is the greateft probability, not to fay certainty, that the lin- 
gular and quick variation of this ftar, during the lpace of feven 
hours, as above mentioned, recurs regularly and periodicals 
about every two days and nearly twenty hours and three 
quarters. 
To afcertain this period with greater accuracy and precilion 
will require more time and obfervation : but I can add, that I 
*' The difference of upwards of an hour in this quotient will eafily be reduced 
to the others by remarking, that Algol was obferved on the ioth and 13th of 
April, not when it was at, but only near, its leaft brightnefs: and, indeed, all 
the little differences of the rell will vanifh by making a real'onable allowance of 
the fame kind. 
R 1* r 2 
have 
