June 8, 191 1] 



NATURE 



501 



from the thirty -seven years' observations now avail- 

 able. 



The principal results for the magnetic elements in 19 lo 

 were : — 



Mean declination 



Mean horizontal force 



Mean dip (with 3-inch needles) 



15° 41 "2" West. 

 0-18532 (C.G.S. units.) 

 66° 52' 37". 



There were no days of "great," and only six of 

 " lesser," magnetic disturbances. 



The mean temperature for 19 10, 497°, was o-i° above 

 the 1841-95 average, but the sunshine recorder showed a 

 deficiency ; July provided only about half the average 

 number of hours of bright sunshine, and May was the 

 only month when the amount was appreciably above the 

 average. The rainfall, 2593 inches, was i-8i inches in 

 excess of the 1841-95 average, and the number of " rainy 

 days " was 175. 



In the time department, the performance of chronometers 

 is reported as satisfactory, and that of chronometer 

 watches as exceptionally good. The increase of electrical 

 devices on board ships having made the question of the 

 magnetic disturbance of chronometers an urgent one, 

 special experiments are being carried out with strong 

 magnetic fields at the observatorv. 



THE HARD AND SOFT STATE OF METALS. 

 Y)R. G. T. BEILBY, F.R.S., delivered the second 

 ■^-^ annual May lecture of the Institute of Metals on 

 Friday, May 12, taking for his subject " The Hard and 

 Soft States in Metals." 



In the course of his lecture Dr. Beilby said that the 

 hardening effect of cold working on ductile metals, and the 

 softening effect of reheating, must have been known to the 

 earliest workers in metals. To the general mind, the 

 phenomena were sufficiently explained as being due to the 

 " compacting " effect of hammering and the "opening 

 up " effect of heat. The advent of scientific methods of 

 inquiry led to the exposure of this fallacy, and to the dis- 

 covery of new points of difference in a metal in the two 

 states. The discovery that the polishing of all substances, 

 even of those so hard or brittle as antimony or calespar, 

 involves the transient liquefaction of a thin layer on the sur- 

 face, led to the study of this subject from an entirely new 

 point of view. In a pure ductile metal which has been 

 slowly cooled from the molten state, the structure of the 

 solid is completely crystalline, and the metal is in its softest 

 condition. Any permanent deformation of the mass, 

 whether by hammering, by rolling, or by wire drawing, 

 hardens and stiffens it. The microscopic examination of 

 the hardened metal shows that its original crvstallino struc- 

 ture has been broken up and replaced by a new type of 

 structure. H ih hardened metal is raised to a sufficient 

 temperature, tli softness is completely restored and the 

 crystalline stmrturf is also restored. In the ductile metals 

 the greatfsi <1, ;_;r of softness is always associated with 

 weil-developod crystallisation. 



The composite character of the hardened structure, 

 which in some cases resembles a bed of broken and dis- 

 torted strata concreted or cemented together by a matrix, 

 can only be explained by the presence of two constituents, 

 namely, the broken-down remains of crystals and an 

 amorphous or glass-like form of the metal by which the 

 mass is so firmly cemented together that it has become 

 vastly more rigid and mfchanirally stable than the crystal- 

 line structure. This amorphous or vitreous form of the 

 inetal stands in the same relation to the crystalline form 

 as glass does to the crystalline silicates of which it is 

 composed, or as the clear, vitreous " barley sugar " does 

 to the ordinary crystals of the breakfast t."ble. 



rh> pure ductile metals cannot be obtained in the 

 vitreous state by cooling, because their molecules retain 

 sufficient mobility lo enable them to marshal themselves in 

 crystalline formation for a range of about 800° brlow the 

 solidifying point. .All the facts show, however, that when 

 liquefaction i-. pKxhirod by mechanicilly induced flow thf^ 

 solidification i'; '-n rapid that the solid which results is in 

 the vitreous condition. 



NO. 



2 171, VOL. 86] 



Microscopic analysis of the surface skin produced by 

 polishing a plate of calcite shows that the disturbance due 

 to poli.shing has penetrated to a depth of one thousandth 

 of a millimetre, and that the subsequent healing over of 

 the disturbance has been so perfect that it can only be 

 explained by the assumption that the transient liquefaction 

 of a layer some thousands of molecules in thickness has 

 occurred. It is evident that the conditions necessary to 

 bring about liquefaction and solidification at the outer 

 surface must equally exist within the substance at all 

 surfaces of slip or shear, and the microstructure of the 

 hardened metal confirms this view. 



The direct bearing of these researches on the obscure 

 subject of molecular structure in solids was pointed out, 

 and a " pulsation cell " hypothesis of the three states of 

 matter was outlined. 



Prof. Quincke's " foam-cell " theory of solidification was 

 referred to, and was applied to the explanation of certain 

 observations made by Prof. Carpenter some years ago. In 

 view of the possible bearing of this theory on questions of 

 foundry practice, it was suggested that the Institute of 

 Metals might offer a prize for the best research on the 

 subject. 



HYDRO-ELECTRIC PLANTS IN NORWAY 

 AND THEIR APPLICATION TO ELECTRO- 

 CHEMICAL INDUSTRY.' 

 'T'HE physical configuration of Norway is remarkably 

 favourable for the utilisation of the large number of 

 waterfalls to be found on the seaboard of the mountain 

 chains which almost cover the country, and through the 

 valleys of which the enormous quantity of water pre- 

 cipitated from the western and south-eastern sea breezes 

 finds its way as rivers flowing down to the son. In the 

 winter the rainfall takes the form of sim. 'it the 



volume of water brought down by the i it its 



greatest from May to July, when the snu\v> mm u v-n the 

 mountains. To make use of the water-power, storage is 

 therefore necessary, and for this the nature of the country 

 is peculiarly adapted, being covered with lakes that have 

 very contracted outlets, and which can be easily converted 

 by damming into storage reservoirs. Thus in the water- 

 shed of Skien the natural water-power of 50,000 horse- 

 power has been increased to an available horse-power of 

 375,000, while the Mosvand reservoir has increased the 

 water-power of the Rjukan factories from 30,000 to 250,000 

 horse-power, with a capital outlay of only some 85,000!. 



The total water-power in Norway has been estimated at 

 from five to seven million horse-power, but as much of the 

 country has not been hydrographically surveyed, this is 

 probably too low an estimate. The power stations can 

 supply power at from 225. to 44s. per e.h.p.-year, and in 

 some cases even for less ; and as the quantities available 

 are as high as from 50,000 to 100,000 horse-power for a 

 sinj,'le fall, the conditions are ideal for the development of 

 clicirochcmical and electrometallurgical indiKtries. Many 

 siuh industries have already reached an .ulv.nKed stage of 

 development. Thus nearly 180,000 horse-powrr will be 

 utilised this year in the manufacture of nitrates of liine, 

 soda, and ammonia from the air by the Birkeland-Eyde 

 process and the Badische Analin und Sodafabrik Com- 

 pany's process ; about 60.000 horse-power are employed in 

 the manufacture of calcium carbide, and other electro- 

 chemical and electrometallurgical industries absorb at 

 present some 20,000 horse-power. Now that a suitable 

 electric furnace — the Gronwall — has been designed for the 

 smelting of iron ore, a furnace that has yielded excellent 

 results on a practical scale, electric iron and steel smelt- 

 ing is likely to develop largely in the hear future, for 

 Norway possesses extensive deposits of iron ore. Three 

 plants, aggregating 16,000 horse-power, with provision for 

 increasing to nearly 60,000. are now being erected at 

 Hardanger, .Arendal. and Tinfoss. Other ores, notably 

 copper, nickel, zinc, will also possibly be electrically 

 smelted at no distant date. 



The second portion of the paper descrilx s in some de!ail 

 the vjiioiis hvdro-eleclric schemes now ' 



' -,.,,,,,,,y of ,T paper read hefore tlie K.ai:i a 

 ii-HanMn, of Christiani*. 



