The daily morning journal and courier., 1898-02-28
AN INSTRUCTIVE LECTURE
PROF. F. J. KEELER TALKED ABOUT
 THE "MOON."
Fourth of the Course Given In the Shelf field Scientific school-Illustrated by Stereoptican Views.

Fourth or the course Given Tn tne Shei-
 field Scientific school-Illustrated by
 Stereoptican Views.
 The fourth lecture of the Sheffield Scientific school course was given in North Sheffield hall Friday night by Professor E. J. Keeler, his subject be- ing "The Moon" It was intensely in teresting from start to finish and high ly instructive. Professor Keeler is graduate of Johns Hopkins University, and after finishing his college course studied under Professor Hastings. For so young man the distinction which Professor Keeler has achieved is lit | tie short of marvellous. He is in full charge of the Allegheny observatory, and is member of the National Acad- emy of Science. The audience present l filled the assembly rooms to the doors and many could not obtain seats The professor began by instancing some of | the ridiculous and over drawn state- | ments made in various books by we'll | known writers concerning the size, condition, composition, etc., of the moon. It is always represented as too large because to the observer it looks larger than it really is. Sometimes it is magnified in size thirty times. This idea of exaggeration is partially satis- | factorily explained by a well-known German painter, who said it was made l so large in order that the proper amount of light could be secured
 Many people ask the questions, l What keeps the moon in the sky and | why doesn't it fall into space? These questions puzzle many, but it can be | easily answered. In the first place nc propelling force is necessary to keep. it up. There is no friction on the moon because of no air. The force of gravi- l ty extends as far as we can go This force of gravity causes the moon to drop one-twentieth of an inch toward the earth in a revolution and keeps it from flying off into space. If this at traction should be increased the moor would move off in a straight line and continue going forever. Astronomers cannot explain how this nebular mass first received it's momentum. There must have been some great propellins force in time past to keep the moon ir
 motion. It revolves on it's own axis once the earth and in the same direc.
 tion. It moves on it's axis with uni
 form velocity while it's revolution abou
 the earth is with variable ve
 locity. We can only see four
 sevenths of the moon, and a. it is impossible to find any trace of in habitants on the part that we can see
 it is highly improbable that any one lives on the other three-sevenths, the part which we cannot see. If the moor is considered as a satellite 1t is very large The mountains on the moon are much sleeper than those on the earth because of the absence of water and air. The speaker explained how the livery many craters and rough places were formed on the moon, as having been the results of a swelling of the hardened crust by the force of interio, gases. A portion of the surface would be raised and then depressed; some o1 it settling down fiat, while the other parts would remain rough and hilly
 The interest in the lecture was greatly
 increased by the stereopticon views
 taken for the most part from the lates'
 photographs of the moon, which have
 been pronounced exceptionally fine
 The methods used in photographine
 the moon by means of the great tele
 scopes were fully explained