VOL. LXXV.] PHILOSOPHICAL TRANSACTIONS. 6()5 



to class them. The 1st precedes v Aquarii 5 m .4 in time, and is l' more north. 

 I have examined it with the powers of 71, 227, 278, 460, and g32 ; and it 

 follows the laws of magnifying, so that its body is no illusion of light. It is a 

 little oval, and in the 7-feet reflector pretty well defined, but not sharp on the 

 edges. In the 20-feet, of 18.7 inch aperture, it is much better defined, and 

 has much of a planetary appearance, being all over of a uniform brightness, 

 in which it differs from nebulas : its light seems however to be of the starry 

 nature, which suffers not nearly so much as the planetary discs are known to do, 

 when much magnified. 



The 2d of these bodies precedes the 13th of Flamsteed's Andromeda about 

 l m 6 in time, and is 22' more south. It has a round, bright, pretty well defined 

 planetary disc of about 12" diameter, and is a little elliptical. When it is viewed 

 with a 7-feet reflector, or other inferior instruments, it is not nearly so well de- 

 fined as with the 20-feet. Its situation with regard to a pretty considerable star 

 is, distance (with a compound glass of a low power) 7' 51" 34'". Position 

 12° 0' s. preceding. Diameter taken with 278, 14" 42'". 



The 3d follows b (Fl. 44) Ophiuchi 4 m .l in time, and is 23' more north. It 

 is round, tolerably well defined, and pretty bright ; its diameter is about 30'. 



The 4th follows n Sagitta 17 ra .l in time, and is 2' more north. It is perfectly 

 round, pretty bright, and pretty well defined ; about a min. in diameter. 



The 5th follows the 21st Vulpeculae 2 m .l in time, and is 1° 46' more north. 

 It is exactly round, of an equal faint light throughout, and about l' in diameter. 



The 6th precedes h (Fl. 39) Cygni 8 m .l in time, and is 1° 26' more south. 

 It is perfectly round, and of an equal faint light ; its diameter near 1', and the 

 edges well defined. 



The planetary appearance of the first 2 is so remarkable, that we can hardly 

 pose them to be nebulae ; their light is so uniform, as well as vivid ; the dia- 

 meters so small and well defined, as to make it almost improbable they should 

 belong to that species of bodies. On the other hand, the effect of different 

 powers seems to be much against their light being of a planetary nature, since 

 it preserves its brightness nearly in the same manner as the stars do in similar 

 trials. If we would suppose them to be single stars with large diameters, we 

 shall find it difficult to account for their not being brighter ; unless we should 

 admit that the intrinsic light of some stars may be very much inferior to that of the 

 generality, which however can hardly be imagined to extend to such a degree. We 

 might suspect them to be comets about their aphelion, if the brightness as well as 

 magnitude of the diameters did not oppose this idea; so that after all, we can hardly 

 find any hypothesis so probable as that of their being nebulas ; but then they 

 must consist of stars that are compressed and accumulated in the highest degree. 

 If it were not perhaps too hazardous to pursue a former surmise of a renewal in 



