i 34 Mr, Pigott-’s 1 Qhfervathm 
Hours. 
1784, Sept. 30. at 1 8 'j 
061. 15, at 1 4 1 Similar Qbfervations ' to that of 17832 
Od. 22. at 19^ July 27th, at 10 h. =fc, y Antinoi being 
Nov. 12. at 14 1 equal to or rather lefs than P Aquilae* 
Nov. 1 1 9. at 14 J 
In eftimating the above times, I paid mtidli attention to the 
obfervations of the, preceding and following days ; however, 
few hours more or lefs do not make a material difference* Tho 
refults of thefe comparifons are 
D. H. M. 
7 4 #1 
7 4 44f 
7 4 5dv 
7 -4 541 
7 4 32 
,7 4 26I 
7 4 .32 
7 4 42I 
7 4 43 - ) 
7 4 2d 
7 4 2 if 
‘On a mean 7 4 38— length of a fingle period. 
As this approaches the mod: to the .preceding refult, it may be 
aflumed as neared: the truth, provided the changes be uni* 
formly periodical. 
Hitherto the opinion of aftrononiers concerning the changes 
of Algol’s light feem to be very unfettled ; at lead: none are 
univerfally adopted, though various are the hypothefes to 
account for it ; fuch, as fuppofing the ilar of fome other than 
a fpherical 
