208 



NATURE 



[October 21, 191 5 



The origin of certain valleys in Cleveland, Cumber- 

 land, and elsewhere, which have generally been attri- 

 buted to overflow streams from ice-dammed lakes, 

 has been investigated by Prof. T. G. Bonney. His 

 conclusions are published in a pamphlet (" On Certain 

 Channels," Bowes and Bowes, Cambridge, 1915). 

 Prof. Bonney contends that these channels are relics 

 of an ancient drainage system, in the case of the 

 Cleveland ones, post-Jurassic, if not post-Cretaceous, 

 and in the case of the Cumberland ones, probably 

 pre-Triassic ; but, at any rate, in all cases long anterior 

 to the Ice age. 



In the Bulletin of the American Geographical 

 Society (vol. xlvii., pp. 672-80) Prof. R. de C. Ward 

 returns to the discussion of the climatic subdivisions 

 of the United States. Such divisions must be chosen 

 in relation to cyclonic and anticyclonic tracks and 

 movements, and local and characteristic weather dis- 

 tribution around high and low pressures. Changes 

 in climate in the United States are met with in going 

 east and west, and not north and south. The climatic 

 subdivisions must therefore be separated by meridional 

 and not latitudinal lines. East and west boundaries 

 are largely arbitrary. The main divisions arrived ^it 

 are five, an eastern province and a gulf province, both 

 bounded on the west by the 2000-ft. contour, that is, 

 about 100° W., a plateau province extending west to the 

 generalised line of the main Rocky divide, a plateau 

 province bounded on the west by the Sierra Nevada- 

 Cascade divide, and a Pacific province. The last three 

 are subdivided into northern and southern regions 

 about 43° N. 



The use of a new type of submarine for hydro- 

 graphical work is described by Mr. Simon Lake in the 

 Scientific American (vol. cxiii., No. 13, September 25). 

 The submarine employed is connected with a surface 

 vessel by an access tube. Power is transmitted from 

 a dynamo on the surface vessel to the submarine, 

 which is provided with a single pair of toothed driv- 

 ing wheels at its bows, capable of being turned in 

 any direction. From the air chamber in the sub- 

 marine a diver can leave the vessel to examine the 

 sea bottom. The author advocates the use of this 

 type of vessel in pairs for harbour contouring. Two 

 such vessels, each with its surface vessel, and linked 

 together by two wires, the upper for telephoning pur- 

 poses, and the lower one to locate obstructions, steer 

 parallel courses half a mile apart. Any obstruction 

 between the submarines would cause a pull on the wire, 

 and the rock could then be located by one of the vessels 

 steering towards it, reeling In the wires as It went. 

 Mr. Lake omits to say whether his method has proved 

 practicable. If successful it would certainly give 

 more accurate hydrographical data than can be ob- 

 tained by the sounding machine alone. 



An earthquake was felt throughout a large part of 

 Cumberland and in- the surrounding counties on 

 October 2 at about 3.15 a.m. The disturbed area, 

 which extends from Newcastleton in Dumfriesshire on 

 the north to Langdale and Troutbeck on the south, 

 and from Silloth on the west to beyond KIrkoswald on 

 the east, is about fifty-five miles long from north to 

 south, and about thirty-seven miles wide, and con- 

 NO. 2399, VOL. 96] 



tains about 1600 square miles. It thus seems almost 

 co-extensive with the disturbed area of the Carlisle 

 earthquake of July 9, 1901 (Quart. Journ. Geol. Soc, 

 vol Iviil., 1902, pp. 371-6). This earthquake, accord- 

 ing to Dr. Davison, was a twin earthquake, originat- 

 ing in a long deep-seated fault directed N. 5° E., 

 underlying the complicated formations of the Lake 

 District. The principal focus was situated seven miles 

 south-south-west of Carlisle, the other more than 

 twenty miles to the south. 



Prof. A. McAdie discusses temperature Inversions 

 in relation to frost (Blue Hill Meteorological Observa- 

 tions, Cambridge, U.S.A., 1915). He seems to find 

 more difficulty in explaining the radiation frosts that 

 occur In sheltered valleys than there really is, for the 

 commonly given explanation Is quite simple and meets 

 the facts so far as they are known perfectly. The 

 first requirement is free radiation, which means 

 absence of cloud of any kind and also absence of 

 water vapour in the overlying air strata; the second 

 is absence of wind. Given free radiation, the ground 

 is rapidly cooled, and imparts its coldness to the 

 bottom layer of air. When this occurs on the summit 

 or slope of a hill the cold air simply runs off down 

 the slope just as water would do, and its place is 

 taken by warmer air from above ; hence on the sum- 

 mit or slope there Is no great fall of temperature. 

 But on a plane or in a valley bottom the case is 

 different, because the chilled air cannot run off and the 

 chilling effect of radiation is continued upon the same 

 air, which therefore reaches a low temperature. Under 

 such conditions there Is naturally a sharp temperature 

 inversion a short distance above the ground. Absence 

 of wind is a further requisite because wind would mix 

 up the different layers of air, thus warming the lower 

 and cooling the higher, but with free radiation at 

 night there Is generally a calm on the surface, though 

 there may be a good breeze a little way up. Prof. 

 McAdie then discusses the artificial means by which 

 damage to growing crops may be reduced or avoided. 



Prof. E. Buckingham, of the Washington Bureau 

 of Standards, sends us several recent papers by him 

 dealing with the principle of similarity and the 

 method of dimensions as applied to the formulation 

 of equations representing physical results. Two of 

 these papers are published In the Physical Review, 

 Iv., 4 (October, 19 14), and the Journal of the Wash- 

 ington Academy of Sciences, iv., 13 (July, 1914). In 

 addition, we have a communication to the American 

 Society of Mechanical Engineers, read In June, 1915, 

 and a letter to the Electrician (January 15, 1915) 

 criticising Becker's formula for the windage of fly- 

 wheels, on the ground that the terms are not all of 

 the same dimensions. It is remarkable how prone 

 not only students, but experienced mathematicians 

 and engineers are to write down equations which 

 are obviously of wrong dimensions. After giving 

 numerous illustrations of the method. Prof. Bucking- 

 ham points out that the method is purely formal and 

 algebraical. If certain quantities and no others are 

 connected by a physical relation, the equation con- 

 necting them must necessarily be of a certain form. 

 Any mistake must be due to overlooking one of the 



