The investigation of these objects possesses extraordinary interest. As an index to the true nature of the relation undoubtedly subsisting between the lucid orbs and the “shining fluid” which equally form part of the sidereal system, their hybrid character renders them of peculiar value. Their distribution—so far restricted to the Milky Way and its borders—may perhaps afford a clue to the organisation of, and processes of change in that stupendous collection of worlds. At present, speculation would be premature; what we want are facts—facts regarding the distances of these anomalous objects—whether or not they fall within the range of the methods of measurement at present available; facts regarding their apparent motions; facts regarding the specific differences of the light emitted by them: its analogies with that of other bodies; its possible variations in amount or kind. The accumulation of any sufficient information on these points will demand with every external aid, the patient labor of years; under average conditions at the earth’s surface, it can scarcely be considered as practically feasible. The facility of Dr. Copeland’s discoveries sufficiently sets off the prerogatives, in this respect, of elevated stations; it is not too much to say that this purpose—were it solely in view—would fully justify the demand for their establishment. Towards one other subject which we might easily be tempted to dwell upon, we will barely glance. Most of our readers have heard something of Dr. Huggins’s new method of photographing the corona. Its importance consists in the prospect which it seems to offer for substituting for scanty and hurried researches during the brief moments of total eclipse, a leisurely and continuous study of that remarkable solar appendage. The method may be described as a _differential_ one. It depends for its success on the superior intensity of coronal to ordinary sunlight in the extreme violet region. And since it happens that chloride of silver is sensitive to those rays _only_ in which the corona is strongest, the coronal form disengages itself photographically, from the obliterating splendor which effectually shrouds it visually, by the superior vigor of its impression upon a chloride of silver film.