magnitudes five, eight and a half, and seven, distances 3.6", p. 360 deg., and 90", p. 22 deg., colors white, blue, and reddish. A fine double is epsilon, magnitudes five and eight, distance 3", p. 5 deg.. The nebula No. 4373 is of a planetary character, and interesting as occupying the pole of the ecliptic. A few years ago Dr. Holden, with the Lick telescope, discovered that it is unique in its form. It consists of a double spiral, drawn out nearly in the line of sight, like the thread of a screw whose axis lies approximately endwise with respect to the observer. There is a central star, and another fainter star is involved in the outer spiral. The form of this object suggests strange ideas as to its origin. But the details mentioned are far beyond the reach of our instruments. We shall only see it as a hazy speck. No. 4415 is another nebula worth glancing at. It is Tuttle's so-called variable nebula. [Illustration: MAP NO. 16.] There are three constellations represented on map No. 16 to which we shall pay brief visits. First Aquila demands attention. Its doubles may be summarized as follows: 11, magnitudes five and nine, distance 17.4", p. 252 deg.; pi, magnitudes six and seven, distance 1.6", p. 122 deg.; 23, magnitudes six and ten, distance 3.4", p. 12 deg.--requires the five-inch and good seeing; 57, magnitudes five and six, distance 36", p. 170 deg.; Sigma 2654, magnitudes six and eight, distance 12", p. 234 deg.; Sigma 2644, magnitudes six and seven, distance 3.6", p. 208 deg.. The star eta is an interesting variable between magnitudes three and a half and 4.7; period, seven days, four hours, fourteen minutes. The small red variable R changes from magnitude six to magnitude seven and a half and back again in a period of three hundred and fifty-one days. Star cluster No. 4440 is a striking object, its stars ranging from the ninth down to the twelfth magnitude. Just north of Aquila is the little constellation Sagitta, containing several interesting doubles and many fine star fields, which may be discovered by sweeping over it with a low-power eyepiece. The star zeta is double, magnitudes five and nine, distance 8.6", p. 312 deg.. The larger star is itself double, but far too close to be split, except with very large telescopes. In theta we find three components of magnitudes seven, nine, and eight respectively, distances 11.4", p. 327 deg., and 70", p. 227 deg.. A wide double is epsilon, magnitudes six and eight, distance 92", p. 81 deg.. Nebula No. 4572 is planetary.