Account of the new Planet ceres. 19^ 



tetters fr6m Sir Henry Englefield, Bart. F. R. S. to Thomas 

 Youngf M. D* F. Rt S. on the Planet Ceres; 



Sir, Blackheath, Friday. 



1 have feert the new pianet twice, on Sunday night, and Obfervattons of 

 again laft night. It is juft vifible to a common night-glafs. Sfs^f^J 

 With a power of 90 in my great lelefcope it was lefs bright giefleldj Baru 

 than the 34 Virginis, near which it is; With a power of 200 

 no difc is vifible, and With 300 I cart fcarcely fay that it has 

 a fenfible diameter, more than what arifes from irradiation^ 

 for fmall ftars feen with filch powers always appear dilated. 



I looked at the Georgian foon after the new planet, but 

 clouds came on, and I did not try 300 on it laft night; With 

 200 the Georgian is, I am fure, the brighter, and it was & 

 very much more vifible object in the night-glafs* 



Sunday; 

 Lafi night I again faw the new planet, and obferved it Its diameter 

 with a power of 400. With this great power it feemed to very * 

 haye an apparent magnitude, but was extremely fmall, faint, 

 and ill defined. I then turned the telefcope to the Georgian 

 (which as you know is very near), and the fuperiority in fize 

 and brightnefs was very ftriking* The Georgian Was not 

 well defined, but I am fure it was full four times the diameter 

 of the new planet, and much brighter in proportion to the 

 different fize. Indeed the brightnefs of the Georgian is very 

 furprifing, its vaft diftance from the fun being confidered. I 

 really think that the diameter of the new planet cannot ex- 

 ceed a fecond ; and it is of a very faint light even for that 

 diameter. I looked then at the double ftar gamma Virginis, 

 and faw the two ftars diftant from each other full three times 

 their apparent diameter, a proof of the good adjuftment and 

 high power of my telefcope. 



I am, &c, 



h. i, 



VIII. Obfervatiom 



