Arizona republican., 1901-03-16
CAUSE OF THE TIDES
The Theory That They Are Que to
 Attraction Is Now Opposed.

Many theories as to the cause of va rious phe nomena have been demolished by the advance of science. It Is only within the past few years, for example. that the belief in the efficacy of the gulf stream to moderate the climate of northwestern Europe has been practi- cally supplanted by an explanation that seems more adequate. Just now the time-honored theory of the cause of tides is being assaulted. It remains to be seen whether the evidence in favor cf the new is so we'll wounded as to relegate the old belief that the mutual attraction of the earth, moon and sun has the peculiar effect upon the sea which results in the tidal wave.
 The opponents of the theory that tides are caused by attraction call at teEtion to the w-rk of the Challeng r expedition in 1872. One of the main ob- jects of this expedition was to solve the problem of ocean currents. The scien- tific world accepted it's demonstration that the circulation of ocean currents is due to differences in temperaIure in the air which cause persistent atmos- pheric currents which drive along with them part of the surface waters of the sea; and also to differences in the temperature of the ocean waters caus- iEg their movements and interming- ling. The moon has no hand in this work. Neither, say the opponents of the tidal theory, is 1t the cause of the other circulation of tn. ocean known as the tides
 MT Alexander Brownie. who sets forth the new theory of the tides in the Bulletin of the American Geographical society. gives many reasons for discred- ting the part assigned to the moon as q tide liter" Among them is the fac that the tide is instantaneous over many degrees of longitude, while the moon takes hours to travel the same distance. The new theorists rely upon gravtation to unlock the tidal myste- ry.
 They say, as Prof. c. H. Darwin does In his book, 'TThe Tides" that the form of equilibrium can never be attained by the ocean. They assert the tide is due to different levels in contiguous masses of water, one mass standing at high ! level immediately contiguous to an- other at low level. It is well known, | for example, that when the tide is high in vast area around the Formulas, ex- tending clear to our coasts, it is low in l the waters of Greenland and the West Indies. The theory is that when the tide is high in this large Bermuda ba- sin, waters must gra asItate toward the i contiguous lower waters In like man. ner. when tide is high in the Greenland | and West Indies basin. it is low in the 1 Bermuda basin, and their high waters gravitate simultaneously toward Der muda's low level thus high levels and low levels on the ocean constantly suc- ceed one another and the tidal phe- romena are produced.
 The theory of gravitation is thus ar rayed against that of attraction as ev- planing tidal phenomena It is well that this scientific controversy has aris- en. Science grows by the knocking over as we'll as the setting up of theo- ries. Truth is often evolved when op- posing theories clash. Some men of science hold that the tidal problem is insoluble; but the present opposition to the old theory may possibly establish the cauce of tides on grounds SO con i vincing that there will no longer be room for divided opinion