SCIENCE 



FRIDAY, NOVEMBER i6, iS 



The drift of public discussion in England, not only among 

 scientists, but also among athletes and others interested in physical 

 training, seems to be against the acceptance of Professor Roy's de- 

 fence of stays and corsets, at the recent meeting of the British 

 Association. Some of the leading journals of London were instant 

 in their approval of Professor Roy's theories ; but where they have 

 done so, immediate protests have come from their readers. The 

 Spectator, for instance, in a recent number, after quoting Professor 

 Roy's assertion that the desire for waist-belts is instructive, and has 

 been displayed by all athletes, and persons of whom exertion is re- 

 quired, since the beginning of history, adds, " ll will be observed 

 that this argument, which is certainly true of all runners, Asiatic or 

 European, applies to men equally with women, though men gird 

 themselves only to meet special calls upon their strength." To this 

 a recent graduate from Cambridge, where he was distinguished as 

 a runner and long-distance bicycle-rider, protests that neither runners 

 nor experts upon the wheel, at that university, ever used, or showed a 

 desire to use, tight waist-belts. On the contrary, it was their custom 

 to gird themselves as loosely as possible in order to allow free move- 

 ment of the diaphragm. If rowers even wear waist-belts, they are 

 so loose as to cause no interference with the freest movements of 

 all the muscles of the body. It is probable that the habit of "gird- 

 ing up the loins " preparatory to physical exertion originated in 

 Oriental countries, where in ancient times, and now as well, the 

 peculiar form of the prevailing costume made it necessary in order 

 to secure free movement of the limbs. A custom once established, 

 needs no further explanation. It may survive long after there is 

 any reason for it. The Hittites wore peaked-toed, turned-up shoes 

 thousands of years after their ancestors had come from the moun- 

 tains of the north, where the form of their snow-shoes suggested 

 the peculiar fashion ; and the daily life of every people is full of in- 

 stances that might be cited. Nobody to day places restraint upon 

 any of his organs if he desires to excel in feats of strength or speed. 

 He may wear a waist-belt, but it is never so tight, as has already 

 been remarked as to rowers, as to interfere with the free play of 

 the muscles. 



The very able paper on hydraulic degradation, by Director 

 J. W. Powell, published elsewhere in this issue of Science, is the 

 result — it would not be safe to say 'the final result ' — of more 

 than a dozen years of study and observation upon the subject. 

 Former publications have simply indicated the direction in which 

 this investigation was proceeding, and announced some of the con- 

 clusions reached. This is a comprehensive, brief, pointed, and 

 easily understood exposition of the whole subject. Science con- 

 gratulates itself upon being the first journal of its class, or of any 

 class, to present this admirable paper to its readers. Major Pow- 

 ell is understood to invite comment, criticism, and discussion of the 

 paper, and Science will gladly open its columns to communications 

 on the subject. 



The approaching resignation of Dr. John B. Hamilton, 

 Surgeon-General of the Marine Hospital Service, to accept the 

 editorship of the Journal of the American Medical Association, 

 adds another to the frequent examples of the difficulty of retaining 

 the bright men of science in the public service. During the last 

 ten years Dr. Hamilton, by his energy and intimate knowledge of 

 the service, has been able to carry out many reforms that could not 



otherwise have been effected. One very important one is the ex- 

 amination of pilots for color blindness, the establishment of new 

 hospitals, the perfecting of the hospital regulations, which amounted 

 to a thorough reorganization of the service and its general advance- 

 ment, until, as Colburn's United Service (London) has declared, it 

 is " the gem of the mercantile marine of the world." The means 

 of preventing the spread of epidemics have been so simplified by 

 Dr. Hamilton that most places subject to epidemic visitations have 

 practically adopted the methods brought into use in this country 

 by him. Dr. Hamilton's remarkable energy will soon make its 

 effect felt in the pages of the Journal. Nothing is slow or dull that 

 he has to do with, not even a medical journal. He will force others 

 to quote from him, instead of making the Journal, as too many 

 similar publications now are, a judicious selection of extracts from 

 the exchanges. His Washington friends, of whom there are many, 

 for he is personally very popular, will regret the loss of his society- 

 but rejoice at his promotion. 



THE LAWS OF HYDRAULIC DEGRADATION." 

 The lands of the earth are degraded by water, by ice, and by 

 winds ; hence in discussing geological degradation it becomes 

 necessary to recognize hydraulic degradation, glacial degradation, 

 and a;olian degradation. 



In hydraulic degradation three methods may be distinguished, i. 

 The surface of the land is disintegrated by various methods and 

 washed away by rains and melted snows. The rains gather into 

 streams, as brooks, creeks, and rivers, and transport the disinte- 

 grated rock from one region to another. This general surface 

 degradation may be called 'erosion.' 2. During the process of 

 this transportation the streams carve channels for themselves, and 

 this channel-cutting may be called ' corrasion.' 3. By erosion, and 

 also by corrasion, cliffs are produced, and these cliffs are broken 

 down by gravity. This method of degradation may be called ' sap- 

 ping.' 



Thus there are three methods of hydraulic degradation, — ero- 

 sion, corrasion, and sapping. 



There are three processes involved in erosion : (a) the rocks are 

 disintegrated; (b) the disintegrated material is transported in 

 water ; {c) in order to be transported in water the material must 

 be loaded. In like manner, there are three processes in corrasion, 

 — disintegration, loading, and transportation. In sapping there 

 are but two processes, disintegration and falling. 



In erosion and corrasion the material which is transported may 

 be called the ' load.' The load is transported by two methods, a 

 portion floats with the water, and another portion is driven along 

 the bottom. The water in which the load floats is the ' vehicle ' 

 of transportation. Gravity is the force of transportation, and acts 

 alike on the water and on the load. In the same sense that the 

 water furnishes its own moving force, through its inherent gravity, 

 so the floating load furnishes its own moving or transporting force 

 through its inherent gravity. Vehicle and floating load alike are 

 moved by gravity. The vehicle can move without the floating load, 

 but the floating load cannot move without the vehicle; that is, the 

 water is the agency of flotation for the load. 



The floating load is in general of greater specific gravity than the 

 water, and while floating, it falls to the bottom and comes to rest, 

 and the progress down-stream of the floating load ends. The ex- 

 cursion which each particle will make from the time it is loaded to 

 the time it is deposited depends upon four conditions : First, spe- 

 cific gravity. If the specific gravity is greater, the particle is de- 

 posited sooner ; if the specific gravity is less, the particle is carried 



* A paper rc.-id before the National Academy of Sciences at its meeting in New 

 Haven, November, iSS3. 



