distinguished authorities, to wit, Sir John Herschel, Humboldt, and Arago; and in general the clearing may be accepted as a meteorological fact, though in one case of close examination it has been negatived. It cannot be doubted that a full moon sometimes shows a night to be clear that would in the absence of the moon be called cloudy. When close comparisons are made between the moon’s positions and records of rain-fall and wind-direction, dim indications of relation exhibit themselves, which may be the feeble consequences of the change of temperature just spoken of; but in every case where an effect has been traced it has been of the most insignificant kind, and no apparent connexion has been recognized between one effect and another. Certainly there is nothing that can support the extensive popular belief in lunar influence on weather, and nothing that can modify the conviction that this belief as at present maintained is an absurd delusion. Yet its acceptance is so general, and runs through such varied grades of society, that we have felt it our duty to dwell upon it to the extent that we have done. CHAPTER XV. CONCLUDING SUMMARY. Having arrived at the conclusion of our subject, it appears to us desirable that we should recall to the reader, by a rapid review, its salient features. Our main object being to attempt what we conceived to be a rational explanation of the surface details of the moon which should be in accordance with the generally received theory of planetary formation, and with the peculiar physical conditions of the lunar globe—the opening of our work was a summary of the nebular hypothesis as it was started by the first Herschel and systemised by Laplace. Following these philosophers we endeavoured to show how a chaotic mass of primordial matter existing in space would, under the action of gravitation, become transformed into a system of planetary bodies circulating about a common centre of gravity; and further, how, in some cases, the circulating planetary masses would themselves become sub-centres of satellitic systems; our earth being one of these sub-centres with only one satellitic attendant—to wit, the moon, the subject of our study. The moon being thus considered as evolved from the parent nebulous mass, and existing as an isolated and compact body, we had next to consider what was the effect of the continued action of the gravitating force. By the light of the beautiful “mechanical theory of heat” we argued that this force, not being _destructible_, but being _convertible_, was turned into heat; and that whatever may have been the original condition of the parent nebulous mass, as regards temperature, its planetary offspring became elevated to an intense degree of heat as they assumed the form of spheres under the influence of gravitation.