August 7, 1890] 



NATURE 



357 



— especially in the matter of cheapness — when he was stopped 

 by the President. The practice Mr. Head follows at meetings 

 of the scientific and technical Societies is not tending to enhance 

 the respect felt for the once honoured name of Siemens. Sir 

 Lowthian Bell said what he said in Paris last year over again. 

 The position he takes up — that no more heat can be got from a 

 ])ound of fuel than Nature put in it— is perfectly sound, but 

 there is no need to repeat the truism at such great length and 

 so often. 



The Sheffield Water Works was the subject of the last paper 

 read at the meeting. 



On the whole, it cannot be doubted that the meeting of 

 the Mechanical Engineers at Sheffield was below the average, 

 and badly managed. If Mr, Eaton's paper on the water- 

 works had been taken as read, and Mr. Addy's contribution 

 on milling cutters had been brought forward, the meeting 

 might have done something to redeem its character as a repre- 

 sentative assemblage of Mechanical Engineers. The Catalogue 

 of the Park Gate Iron and Steel Works might also have been 

 taken as read. Both the latter and the water-works paper were 

 acceptable as guides to the respective excursions, but that was 

 no reason why members should be required to sit and listen 

 whilst Mr. Bache read through them at a speed which rendered 

 it quite impossible to follow. 



We have not space to refer to the visits to works in Sheffield 

 open to visitors, and indeed there was not much of exceptional 

 interest. Exception must be made, however, to a loom for weaving 

 horse-hair cloth, which was seen at the works of Laycock and 

 Sons. The wonderful ingenuity displayed by designers of textile 

 machinery appears here to have reached its culminating point. 

 Horse-hair has several undesirable features from a textile point 

 of view. The filaments are generally no longer than 3 or 4 

 feet ; though exceptional hairs have been known as long as 6 

 feet, we believe. The thickness differs considerably at each 

 end ; the material is very elastic, and it is so hard that it will 

 speedily wear away the hardest steel over which it may be 

 dragged. In order to overcome these difficulties, the designer 

 of this loom, Mr. W. S. Laycock, has introduced a shuttle with 

 jaws that take hold of each hair as it is presented, and a device 

 which is known as the selector. The latter is a hand — for we can 

 call it nothing less — which picks up one hair, and only one, to 

 present to the jaws of the shuttle. It has to let go at the very 

 instant the shuttle takes hold, otherwise the hair would be 

 dragged through its fingers, which would soon be worn away. 

 Sometimes, however, the fingers fail to grasp this single hair ; 

 it must be remembered if it were to take two hairs the cloth would 

 be spoiled. It then makes a second try, and, if the second fail, 

 yet a third. Supposing the third attempt also prove unsuccess- 

 ful, there being no time to make a fourth, the selector promptly 

 stops the weft motion, so that no change takes place whilst the 

 shuttle is making its traverse without a hair to form the weft. 

 Theophrastus Such, after a visit to a textile factory, had a night- 

 mare, in which mechanism usurped the place of humanity, and 

 became the inexorable master of mankind. The conceit is 

 worked out with much skill, and appears quite plausible when 

 viewed in the light of mechanism which not only performs the 

 most delicate operations, but knows when it misses, tries again 

 as long as trying is of avail, and, if it fail at last, takes steps to 

 prevent mischief following. 



ON THE ORIGIN OF THE DEEP TROUGHS 

 OF THE OCEANIC DEPRESSION : ARE 

 ANY OF VOLCANIC ORIGIN?^ 



'T'HE consideration of the question with regard to the origin 

 of the ocean's deep troughs requires, as the first step, a 

 general review of oceanic topography ; for according to recent 

 bathymetric investigations, the deep troughs are part of the 

 system of topography, and its grander part. We need, for this 

 purpose, an accurate map of the depths and heights through all 

 the great area. Such a map will ultimately be made through the 

 combined services of the Hydrographic Departments of the 

 civilized nations. At the present time the lines of soundings 

 over the oceans, especially over the Pacific and Indian, are few, 

 and only some general conclusions are attainable. It is to be 

 noticed that the system of features of the oceanic area are 

 involved in the more general terrestrial system ; but since the 



' This paper is accompanied in the American Journal of Science from 

 which it is reprinted, by a bathymetric map. 



NO. 1084, VOL. 42] 



former comprises nearly three-fourths of the surface of the 

 sphere, it is not a subordinate part in that system. 



With reference to this discussion of the subject I have pre- 

 pared the accompanying bathymetric map. 



L The Bathymetric Map, and the General Features 

 OF the Oceanic Depression displayed by it. 



I, The Map. — In the preparation of the bathymetric map 

 I have used the recent charts of the Hydrographic Departments 

 of the United States and Great Britain, ^ which contain all 

 depths to date, and the lists of new soundings published in 

 German and other geographical journals. In order that the 

 facts on which the bathymetric lines are based may be before 

 the reader a large part of the depths are given, but in an 

 abbreviated form, loo fathoms being made the unit : 25 signify- 

 ing 2500 fathoms or nearly (between 2460 and 2550); 2" 3, 

 about 230 fathoms, -4, about 40 fathoms. Only for some deep 

 points is the depth given in full. The addition of a plus sign 

 { At ) signifies no bottom reached by the sounding." 



In the plotting of oceanic bathymetric lines from the few lines 

 of soundings that have been made, the doubts which constantly 

 rise have to be settled largely by a reference to the general 

 features of the ocean, and here wide differences in judgment 

 may exist in the use of the same facts ; but through the depths 

 stated on the map, the reader has the means of judging for him- 

 self. In the case of an island the lines about it may often have 

 their courses determined by those of adjoining groups, or by its 

 own trend ; but in very many cases new soundings are needed 

 for a satisfactory conclusion. 



Some divergences on the map from other published bathy- 

 metric maps require a word of explanation. The northern half 

 of the North Pacific is made, on other deep-sea maps, part of a 

 great 3000-fathom area (between 3000 and 4000) stretching from 

 the long and deep trough near japan far enough eastward to 

 include the soundings of 3000 fathoms and over in mid-ocean 

 along the 35th parallel. It has seemed more reasonable, in 

 view of present knowledge from soundings, to confine the deep- 

 sea area off Japan to the border-region of the ocean, near the 

 Kurile and Aleutian Islands, and leave the area in mid-ocean ta 

 be enlarged as more soundings shall be obtained. Again, in the 

 South Pacific, west of Patagonia, the area of relatively shallow 

 soundings (under 2OO0 fathoms) extending out from the coast, is 

 on other maps bent southward at its outer western limit so as to- 

 include the area of similar soundings on the parallels of 40" and 

 50°, between 112° and 122° W. The prevailing trends of the 

 ocean are opposed to such a bend, and more soundings are 

 thought to be necessary before adopting it. 



It maybe added here that in the Antarctic Atlantic, about the 

 parallel of 66^° S. and the meridian of 13^'' W., a large area of 

 3000 and 4000 fathoms has been located. It was based, as I 

 have learned from the Hydrographic Department of the British 

 Admiralty, on a sounding in 1842 by Captain Ross, R.N., in 

 which the lead ran out 4000 fathoms without finding bottom. 

 The sounding was, therefore, made before the means available 

 were " sufficient to insure the accuracy of such deep casts." ^ 



2, The Ffattire- lines of tJie Oceanic and Bordering Lands. — The 

 courses of island-ranges and coast-lines have a bearing on the 

 question relating to the courses of the deep-sea troughs, and 



' I am indebted to the Hydrographic Departments of Great Britain as 

 well as the United States for copies of these charts. 



* On the map the bathymetric lines for 1000, 2000, 3000, and 4000 fathoms, 

 besides being distinguished in the usual way by number of dots, have been 

 made to differ in breadtli of line, the deeper being made quite heavy in order 

 to exhibit plainly the positions of the areas without the use of colours. The 

 line for 100 fathoms is, as usual, a simple dotted line. As the bathymetric map 

 herewith published is necessarily small, and none of the ordinary maps of 

 the oceans give either deep-sea soundings or a correct idea of the trends of 

 the oceanic ranges of islands, I state here that the charts of the U.S. 

 Hydrographic Department for the Atlantic, Pacific, Indian, and Arctic Oceans 

 may be purchased of dealers in charts in the larger .sea-board cities for 50 

 cents a sheet and less according to size. (There are several large charts to 

 each ocean.) One of the firms selling them in New York City is that of 

 T. S. and J. D. Negus, 140 Water Street. The British Admiralty have pub- 

 lished a map of the Pacific with its soundings on a single sheet, and 

 for the Atlantic and Indian Oceans with part of the Pacific, besides charts 

 of the Antarctic and Arctic seas. The occasional Bulletins from the Hydro- 

 graphic Department and Petertnann's Mitteilungen contain nearly all the 

 new data issued for the perfecting of such a chart. 



3 The communication received from the Admiralty Office adds that " Some 

 of Ross's soundings up to 2660 fathoms have been proved correct, and hence 

 the sounding in 68° S., referred to, has been retained on our charts until 

 disproved." " Another sounding obtained^ by Ross in the Atlantic has had 

 strong doubts thrown upon it by a sounding of 3000 fathoms obtained not 

 very far from its position." See the accompanying map, near latitude 140 S. 



