between light and darkness (in the crescent or gibbous moon) where this boundary crosses any of the dark places, the line of division is found to be rough and jagged; but were these dark places liquid, it would evidently be even.
The description of the wings of the man-bat, on page 21, is but a literal copy of Peter Wilkins' account of the wings of his flying islanders. This simple fact should have induced suspicion, at least, it might be thought.
On page 23, we have the following: "What a prodigious influence must our thirteen times larger globe have exercised upon this satellite when an embryo in the womb of time, the passive subject of chemical affinity!" This is very fine; but it should be observed that no astronomer would have made such remark, especially to any Journal of Science; for the earth, in the sense intended, is not only thirteen, but forty-nine times larger than the moon. A similar objection applies to the whole of the concluding pages, where, by way of introduction to some discoveries in Saturn, the philosophical correspondent enters into a minute schoolboy account of that planet:—this to the Edinburgh Journal of Science!
But there is one point, in particular, which should have betrayed the fiction. Let us imagine the power actually possessed of seeing animals upon the moon's surface;—what would first arrest the attention of an observer from the earth Certainly neither their shape, size, nor any other such peculiarity, so soon as their remarkable situation. They would appear to be walking, with heels up and head down, in the manner of flies on a ceiling. The real observer would have uttered an instant ejaculation of surprise (however prepared by previous knowledge) at the singularity of their position; the fictitious observer has not even mentioned the subject, but speaks of seeing the entire bodies of such creatures, when it is demonstrable that he could have seen only the diameter of their heads!
It might as well be remarked, in conclusion, that the size, and particularly, the powers of the man-bats (for example, their ability to fly in so rare an atmosphere—if, indeed, the moon have any)—with most of the other fancies in regard to animal and vegetable existence, are at variance, generally, with all analogical reasoning on these themes; and that analogy here will often amount to conclusive demonstration. It is, perhaps, scarcely necessary to add, that all the suggestions attributed to Brewster and Herschel, in the beginning of the article, about "a transfusion of artificial light through the focal object of vision,' &c., &c., belong to that Species of figurative writing which come, most properly, under the denomination of rigmarole.
There is a real and very definite limit to optical discovery among the stars—a limit whose nature need only be stated to be understood. If indeed, the casting of large lenses were all that is required, man's ingenuity would ultimately prove equal to the task, and we might have them of any size demanded. But, unhappily, in proportion to the increase of size in lens, and, consequently, of space-penetrating power, is the diminution of 1ight, from the object, by diffusion of is rays. And for this evil there is no rem-
