122 0N TW0 CELESTIAL BODIES. 



Hazinefs. however, a hazinefs about the ftar, which refembled a faint 



coma; and this, it may be fuppofed, muft render the meafure 

 lefs fatisfaftory than it would otherwife have been. 

 Diameter of Ce- From thefe data we compute, that the difk appeared to the 

 «» ° »3 ■ natural eye under an angle of 3' 14",33 ; while Ceres, when 



magnified 5 1 6£ times, was feen by the other eye of an equal 

 magnitude ; and that confequently its real diameter, by mea- 

 furement, was only 0",38. 

 3. Observation April 22. 1 l h 38', fidereal time. I ufed now a more perfect 

 res^io-feet rel ^* ina ^ m ' rror i tne former one having been injured by long 

 flec"tor, new continued folar obfervations. This gave me the apparent 

 imall mirror j diameters of the flats uncommonly well defined ; to which, 

 perhaps, the very favourable and undifturbed clearnefs of the 

 atmofphere might contribute confiderably. 

 power88i,5i j With a magnifying power of 881,51, properly afcertained, 

 like thofe which have been mentioned before, I viewed Dr. 

 Olbers's ftar, and compared it with a lucid difk of 1,4 inch in 

 diameter, placed at 1514- inches from the eye, meafured, like 

 bad obf. the reft of the diftances, with long deal rods. The ftar ap- 



peared to me fo ill defined, that, afcribing jt to the eye-glafs, 

 I thought it not advifeable to compare the object, as it then 

 Power changed appeared, with a well defined lucid difk. Exchanging the 

 t0 5 1 *• gi a f s f or that which gives the telefcope a magnifying power o'f 



Pallas, 5 16|, I found Pallas, as the difcoverer wifhes to have it called, 



better defined ; and faw, when brought together, that it was 

 confiderably lefs in diameter than the lucid difk. 



In order to produce an equality, I removed the difk to 

 1942 inches; and ftill found Pallas confiderably lefs than the 

 difk. 

 fmaller than Cc- Before I changed the diftance again, I wifhed to afcertain 

 whether Ceres or Pallas would appear under the largeft angle, 

 efpecially as the air was now more pure than lafl night. On 

 comparing the diameter of Ceres with that of the lucid difk, I 

 found it certainly lefs than the difk. By proper attention, and 

 continued examination, for at leafl an hour, I judged it to be 

 nearly { of the lucid difk. 



Then, if we calculate as before, it appears by this obferva- 



tion, in which there is great reafon to place confidence, that 



the angle under which this ftar appeared, was only / '.22. 



For, a lucid difk of 1,4 inch diameter, at the diftance of 1942 



4 inches. 



