ART. CONTENTS OF No. LIII. PAGE I. PHYSICAL CHANGES UPON THE SURFACE OF THE MOON. By V. ON THE LOESS OF THE RHINE AND THE DANUBE. By Mansfield's "Aerial Navigation." . "A Classified English Vocabulary, being an attempt to facilitate a Knowledge of Words and their Meanings by an Ar- Burmeister's "Description Physique de la Republique Argentine." 118 "The Empire of Brazil at the Universal Exhibition of 1876 in Beard's "Hay-Fever or Summer Catarrh; its Nature and Treat- Hagen's "Statistical Investigations on Mental Diseases," Wyman's "Peabody Academy of Science." Potts's "Elementary Arithmetic, with Brief Notices of its History." Coues's "Abstract of Results of a Study of the Genera Geomys and Thomomys, with Addenda on the Osteology of the Geomyidæ and on the Habits of Geomys Tuza." Packard's "United States Geological Survey of the Territories." 128 Proctor's "The Sun-Ruler, Force, Light, and Life of the Pla- PROGRESS IN SCIENCE. THE QUARTERLY JOURNAL OF SCIENCE. JANUARY, 1877. I. PHYSICAL CHANGES UPON THE SURFACE OF THE MOON. By EDMUND NEISON, F.R.A.S., Author of "The Moon, and the Condition and Configuration of its Surface." THE HE present condition of the surface of the moon is one of the most interesting and important questions within the whole range of Astronomy; and being a subject of considerable difficulty, and requiring a thorough acquaintance with more than one branch of science to be properly dealt with, it is not surprising that widely different views on the question are held by different astronomers. The question is, however, of importance to others besides astronomers, and many eminent physicists and geologists have recognised that the study of the present condition of the surface of our satellite promises to throw much light on many vexed geological and physical problems. The opinion of that eminent geologist the late Prof. Phillips on this subject is well known, for he often expressed his conviction that the lunar surface presented the best field for the study of many of the more difficult problems of geology, and under this conviction he devoted many years to the study of selenography. Considering, in fact, the close relationship between the earth and its satellite, and the general analogy that selenographers maintain exist between their respective classes of primitive formations, it is unquestionable that the study of lunar surface must throw light on many obscure points in the past history of the earth, and probably in fact on the general history of the planets. VOL. VII. (N.S.) B The question of the present condition of the surface of the moon has engaged, therefore, the attention of some of the most eminent astronomers, and much has been done towards obtaining the information necessary for the proper consideration of the problem. But though much has been done in this direction, very much more remains to be done before this question can be held to admit of decisive settlement; for though the general nature of the lunar formations and surface has been made out fairly well, the details, which are of the utmost importance, are only very partially understood. The paucity of material available on which astronomers in general may found an opinion is not widely understood, for, with the exception of a few pages in the great work of Beer and Mädler's "Der Mond," and a small work by another great selenographer (Schmidt, of Athens), also entitled "Der Mond," until lately no published information may be said to exist accessible to astronomers in general. Hitherto information, with regard to the details of the structure of the formations on the surface of the moon, has had to be obtained directly by the careful study of the lunar surface,—a work necessarily occupying years, and only to be acquired by assiduous labour. These particulars, though not at first sight of importance, must not, however, be overlooked, for it will subsequently appear that they go far to explain the position now occupied by the question-What is the present condition of the lunar surface? It is a remarkable circumstance, in relation to this question, that whereas those astronomers who have devoted much time and labour to the study of the moon's surface, and to whom astronomers in general are mainly indebted for our present knowledge of the surface of our satellite, hold in general one view as to the present condition of the lunar surface, astronomers as a body hold a very different opinion. To take a striking instance,-scarcely any astronomer known to have devoted time to the study of selenography doubts that many processes of actual lunar change are in progress, and it is doubtful if there is one who could not promptly instance one or more such cases. Yet the general opinion of astronomers appears to be against any such physical changes having occurred. And another instance, almost as striking, exists in connection with the subject of the lunar atmosphere: whilst all selenographers appear to have detected instances where the existence of this atmosphere is revealed, astronomers in general appear to question almost the possibility of its existence, and this in face of the absence of any evidence |