The star 70 Ophiuchi, a fourth-magnitude star on the right shoulder of Ophiuchus, is a noted double. The distance between the components about 5-1/2", their magnitudes 4-1/2 and 7, the colours yellow and red. The pair form a system whose period of revolution is about 95 years. 36 Ophiuchi (variable), distance 5".2, magnitudes 4-1/2 and 6-1/2, colours red and yellow. [rho] Opiuchi, distance 4", colours yellow and blue, magnitudes 5 and 7. Between [alpha] and [beta] Scorpionis the fine nebula 80 M may be looked for. (Or more closely thus:--below [beta] is the wide Double [omega]^{1} and [omega]^{2} Scorpionis; about as far to the right of Antares is the star [sigma] Scorpionis, and immediately above this is the fifth-magnitude star 19.) The nebula we seek lies between 19 and [omega], nearer to 19 (about two-fifths of the way towards [omega]). This nebula is described by Sir W. Herschel as "the richest and most condensed mass of stars which the firmament offers to the contemplation of astronomers." There are two other objects conveniently situated for observation, which the observer may now turn to. The first is the great cluster in the sword-hand of Perseus (see Plate 4), now lying about 28 deg. above the horizon between N.E. and N.N.E. The stars [gamma] and [delta] Cassiopeiae (see Map 3 of Frontispiece) point towards this cluster, which is rather farther from [delta] than [delta] from [gamma], and a little south of the produced line from these stars. The cluster is well seen with the naked eye, even in nearly full moonlight. In a telescope of moderate power this cluster is a magnificent object, and no telescope has yet revealed its full glory. The view in Plate 5 gives but the faintest conception of the glories of [chi] Persei. Sir W. Herschel tried in vain to gauge the depths of this cluster with his most powerful telescope. He spoke of the most distant parts as sending light to us which must have started 4000 or 5000 years ago. But it appears improbable that the cluster has in reality so enormous a longitudinal extension compared with its transverse section as this view would imply. On the contrary, I think we may gather from the appearance of this cluster, that stars are far less uniform in size than has been commonly supposed, and that the mere irresolvability of a cluster is no proof of excessive distance. It is unlikely that the faintest component of the cluster is farther off than the brightest (a seventh-magnitude star) in the proportion of more than about 20 to 19, while the ordinary estimate of star magnitudes, applied by Herschel, gave a proportion of 20 or 30 to 1 at least. I can no more believe that the components of this cluster are stars greatly varying in distance, but accidentally seen in nearly the same direction, (or that they form an _enormously long system_ turned by accident directly towards the earth), than I could look on the association of several thousand persons in the form of a procession as a