102 
The nebula on the north is M. 82, and appears as a bright ray, 
due to its being viewed edgewise from our position on the earth. 
A nebulous star is also visible on the south, near the edge of the 
plate. 
Next is the photograph (Pl. ix.) of the dumb-bell nebula in Vul- 
pecula, -Jt is in R.A. 19 h. 255. m.,.decl. N.. 22 dep /2eanuaaaan 
covers a sky area of 1 deg. 26 m. by 1 deg. 13m. ‘The scale is 18 
seconds of arc to 1 millimeter. It was taken with the twenty-inch 
reflector, on October 3, 1888, with an exposure of three hours. 
The drawings of the nebula by Herschel and Lord Rosse are famil- 
iar as illustrations in text-books, but when they are compared with 
the photograph they fail to show the outlines and details which it 
reveals. The brighter part is not shown in the shape of a dumb- 
bell, strictly, but as a vast, globular mass, surrounded by a wide, 
nebulous ring, which is seen as a projection at both sides and 
encroaching on the globular mass, which is also broken up into 
flocculent patches. 
Next is the photograph (Pl. x.) of the nebule in the Pleiades. 
The sky area shown is 1 deg. 26 m. by 1 deg. 13 m., on a scale of 
18 seconds of arc to 1 millimeter. The photograph was taken with 
the twenty-inch reflector, December 8, 1888, with an exposure of 
four hours. ‘The stars visible to the eye in the Pleiades are five in 
number, and in 1859 Tempel discovered that the star MWerope was 
involved in faint nebulosity. Some further traces of nebulous light 
in the group were suspected in a vague, indefinite way, by Weiss 
and other observers using large telescopes. In 1885, the Henrys 
obtained a photograph which showed a trace of nebulosity near 
three of the bright stars ; namely, three streamers across MWerope, 
and a little projection from AZaza, also a horn-like projection from 
Lilectra. My first photograph—taken in December, 1886, with 
three hours’ exposure—proved the existence of extensive nebulous 
patches and streamers scattered over the whole group and probably 
forming parts of one vast nebula. The present photograph exhibits 
these features as far as they are at present known. 
Next are two photographs (Pls. xi. and xii.) of the great nebula 
in Orion. ‘The sky area covered is 1 deg. 16 m. by 1 deg. 4 m., on 
a scale of 16 seconds of arc to 1 millimeter. Pl. xi. was taken with 
the twenty-inch reflector, December 24, 1888, with an exposure of 
eighty-one minutes. ‘The other (PI. xii.), with an exposure of three 
hours and twenty-five minutes, was taken on February 4, 1889, 
