2§Q MAGNITUDE OF SMALL" CELESTIAL BODI |. 



which it appeared was 2' 18",9, and tbat witla a high powe* 

 (522) a part of it, fublendingan angle of O v ,364- may be con- 

 veniently perceived. 



When the purpofe of this experiment, Was confidered, the 

 refult was not found fufficient to anfwer the intention ; for as 

 the fifce of the object reqaired the ufe of a low power, a doubt 

 arofe whether the inurnment would be equally diftincl when 

 a higher fliould be required. To refolve this queftion, it was 

 neceflary either to remove my objects to a greater diftance, 

 or to make them fmaller. 

 With globules <2. Small globules of fealing-wax were therefore made bf 

 dipping the point of a fine needle, a little heated,' into it, 

 which took up a fmall globule. To prevent feeing them at a 

 diftance in a different afpect from that in which they were 

 meafured under the microfcope, the needles were fixed with 

 fealing-wax on fmall flips of cards before the meafures were 

 taken. 



By this experiment it was found, that with a globule fo fmall 

 as ,00763 of a fubflance not reflecting much light, the mag- 

 nified angle rauft be between 4 and 5 minutes before we can 

 fee it round. But it alfo (hewed that a lelefcope with a fuffi- 

 cient power (522) will (how the difk of a faint object when 

 the angle it fubtends as the neked eye is no more than 0",653. 

 Globules of fil- The third experiment was made with globules of filver. As the 

 objects made of fealing-wax, on account of their colour, did 

 not appear to be fairly felected for thefe investigations, a fet 

 of filver ones were made. They were formed by running 

 end of filver wires, the 305th and 340lh part of an inch dia r 

 meter, into the flame of a candle./ 



By this experiment it was found that the telefcope acted very 

 well with a high power (522), and will (how an object fub- 

 tending only 0",484 (q large that it may be divided into quar- 

 ters of its diameter, 

 Experiments The fourth experiment was made with globules of pitch, 



with other gte- bee's-wax, and brimftone, and did not prove fo generally ad* 

 fih/e/at greater vantageous as thofe with filver which reflected more light. 

 Nuances, &c And a fifth and fixth experiment was made with the filver 

 globules at greater diflances; and by illuminations at night 

 by the flame of a lamp of which for brevity the particulars, are 

 here omitte<2% 



The 



