60 Kansas Academy of Science. 



that spot of the prolunar hemisphere directly under the satellite ; 

 but being 60 times as far distant, its power is but -j^Vtt o^ what it 

 would be in the assumed position ; and if we allow its counterbal- 

 ancing effect on the normal avoirdupois pound as ^j^^ of a grain, we 

 make a very liberal concession. This is a ratio of 1 to 280,000 

 compared with the earth's influence in weight making. With this 

 vast difference in degrees of ponderal powers, it seems like the 

 shadow of a metaphor to attribute a capacity to our great sunlight 

 reflector to pull up from the normal level millions of tons of water 

 in opposition to nearly 300,000 times its own potency. But what we 

 speak of as the subtrahend of terrestrial weight, or the pulling force 

 of the moon, is really but an index of the tendency of the water to 

 leave the earth and go to the moon, an impulse inherent in the 

 water itself and not in any extrinsic pulling force, and which, 

 measured by its tendency to remain, is as 1 to 280,000. It is true 

 there must be a differential in degrees of tendency between surface 

 waters and deep layers, but this is too slight to produce an ob- 

 servable effect. If a pulling power would draw the waters toward 

 the eastern shores, it would draw them away from the western 

 shores, and the tides there would be but the effect of their return- 

 ing to the normal. It may be possible to measure mechanically 

 with a torsion fiber and a long index finger over a large dial the 

 supposed power of the moon. I am not aware that the attempt has 

 been made. It would be a great triumph of skill and science, if 

 successful. 



Yet in that case how could the effect of the approach of the 

 geolunar gravity center to the sublunar terrestrial surface be ex- 

 cluded from the elements entering into the difficult experiment and 

 its results ? Unfortunately the dynamics of the tides have been 

 made a datum for calculating the moon's mass, with a likelihood of 

 having derived too large a quantity as a conclusion. It is quite 

 possible, if not probable, that its ratio of mass to that of the earth's 

 is not even 1 to 100, instead of 1 to 80. If the satellite is an off- 

 spring of the earth, which appears a very proper inference from 

 what we know of cosmic physics of solar action and extraplanetary 

 conditions, it was born when our globe had a gaseous or liquid 

 constitution from center to circumference, and was much more 

 oblate than at present, and must be mostly composed of the light- 

 est metals and metalloids. Nor is it probable that since that time 

 it has ever enlarged its orbital circuit — on the contrary, it is more 

 likely to have contracted it, for reasons which are given in another 

 paper. 



