What origin do they attribute to these rifts? That is a question difficult to solve. They are certainly anterior to the formation of craters and circles, for several have introduced themselves by breaking through their circular ramparts. Thus it may be that, contemporary with the later geological epochs, they are due to the expansion of natural forces. But the projectile had now attained the fortieth degree of lunar latitude, at a distance not exceeding 40 miles. Through the glasses objects appeared to be only four miles distant. At this point, under their feet, rose Mount Helicon, 1,520 feet high, and round about the left rose moderate elevations, enclosing a small portion of the "Sea of Rains," under the name of the Gulf of Iris. The terrestrial atmosphere would have to be one hundred

