288 
Dr. Herschel’s Astronomical Observations 
more numerous. The following 101 double nebulas referred 
to will confirm this statement.* 
No. 36 and 37 in the first class are “ Two small bright 
“ nebulas, both a little extended/’ 
No. 74 and 75 in the second class are “ Two pretty bright 
“ nebulae ; the preceding of them is almost round ; the fol- 
“ lowing very much extended in length ; they are not far 
“ from the same parallel, and about 8 or io' distant from each 
44 other.” 
No. 127 and 128 in the third class are “ Two extremely 
“ faint nebulas, about 3' from each other, and nearly in the 
“ same parallel. The second is a very little brighter than the 
“ first, and is of an irregular round figure.” 
It is remarkable that in the description of all these 101 ne- 
bulas, there are not more than five or six which differ so much 
in brightness from one another, that we could suppose them 
to be at any considerable different distance from us ; and equal 
brightness or faintness runs through them all in general ; but 
supposing that any two nebulas should even differ as much 
from one another, as the set of the first class which has been 
described, is different from the faintness of the last described 
set, yet this would not nearly amount to the difference in the 
brightness of one part of the nebula in Orion from that of 
another of the same nebula. 
* See I. 28, 3 6, 90, 145. II. 1 7, 44, 55, 61, 74, 84, 85, 115, 118, 121, 139, 153, 
167,219,228, 233, 333, 388,426,429,455, 518, 546, 550, 580,614,679,684, 
692, 751, 764, 787, 789, 841, 842, 865, 868. III. 9, 15, 35, 44, 51, 62, 97, 117, 
i2i, 127, 129, 138, 154, 159, 162, 166, 167, 172, 196, 199, 210, 216, 231, 250, 277, 
306, 323, 335, 344, 351, 377’ 4° 2 > 4°4> 4°7> 4 l6 > 4 22 > 43 1 * 54 6 > 55^ 572, 574, 
592, 629, 635, 657, 678, 707 } 758, 781, 798, 800, 802, 807, 869, 897, 917, 957, 
959’ 974- 
