468 



NATURE 



[June i6, 1910 



tropic transformation which metallic tin undergoes at 

 moderately low temperatures. More interesting, because 

 of far wider importance, however, are his observations 

 and views on what he terms the " maladie d'^crouissage ' ; 

 this is, in realitv, simply a process of spontaneous anneal- 

 ing or re-crystallisation which occurs in certain circum- 

 stances in metals which have been severely hardened by 

 plastic strain. So long ago as 1900 Ewing and Rosen- 

 hain showed that when pure lead has been freshly crushed 

 or rolled, the minute crystals commence to grow, even at 

 the ordinary temperature, at a rate which produces visible 

 changes in a. few weeks. Prof. Cohen's observations show 

 that processes of this kind are not confined to lead, but 

 occur also in harder materials, especially in hard-drawn 

 brass, thus accounting for the spontaneous cracking of 

 cartridge-cases which occasionalh' occurs in practice after 

 a lapse of several years from the date of manufacture, on 

 the view that the re-crystallisation process is accompanied 

 by a change in volume. The whole process is favoured by 

 any rise of temperaiture, so that the phenomena are more 

 readily observed in hot climates. Whether such action 

 takes place at possibly a still slower rate in iron and steel 

 is a problem still to be investigated. An important fact 

 brought out by Prof. Cohen's experiments, however, is 

 that the process of re-crystallisation is initiated and 

 accelerated by intimate contact with a piece of the same 

 metal in the stable or " annealed " condition ; it is, indeed, 

 this phenomenon which leads Prof. Cohen to describe the 

 whole process as an " infectious disease " of metals. 



The Engineer for June 3 contains a description of the 

 Druitt Halpin system of thermal storage recently installed 

 at the King's Road works of the St. Pancras Borough 

 Council Electricity and Public Lighting Department. 

 Each of four water-tube boilers has been fitted with 

 a storage vessel, and some figures regarding the perform- 

 ance of the plant are certified by Mr. Baynes, the borough 

 electrical engineer. Each boiler, as originally installed, had 

 a maximum normal evaporation of about 11,000 lb. per 

 hour. One boiler fitted with a thermal storage drum was 

 run for 2h. 51m., the storage dnun being full at the 

 start and empty at the finish. During this time the 

 average evaporation per hour was found to be 17,542 lb., 

 or an increase of 59-5 per cent, more than the normal. 

 During this test the average working pressure was 185 lb. 

 per square inch, the temperature in the drum 360° F., 

 and the draught at the boiler exit 0-5 inch by water-gauge. 

 With this system it is found that deposits from hard water 

 are found in the storage drum rather than in the boiler, 

 and are therefore not subjected to the heat of the furnace, 

 which would bake them to a hard scale. Such deposits 

 are very easily blown off from the storage drum in a soft 

 powdery state. 



Messrs. Longmans, Green and Co. have published a 

 third edition of Dr. F. Mollwo Perkin's " Qualitative 

 Chemical Analysis: Organic and Inorganic." The first 

 edition of the work was reviewed in our issue of August 22, 

 iQoi (vol. Ixiv., p. 397), and it is sufficient to point out 

 that to the present issue has been added a short section 

 dealing with some of the rarer elements and a new chapter 

 on ethereal salts. 



A THIRD edition of Mr. Walter B. Priest's " Scheme for 

 the Promotion of Scientific Research " has been published 

 by Messrs. Stevens and Sons, Ltd. We dealt with the 

 second edition somewhat fully in our issue of January 21, 

 1909 (vol. Ixxix., p. 345). In the present edition the 

 administration of grants has been further explained, and 

 the author of the book proposes terms of allocations of 



NO. 2120, VOL. 83] 



grants in relation especially to electrical science. The 

 author hopes that the advantages to be gained by legis- 

 lating for the promotion of scientific research, where it 

 affects purposes of general utility and advantage, will 

 receive serious consideration. 



, OUR ASTRONOMICAL COLUMN. 



The Meteor of June i. — Further observations of the 

 large meteor of June 1 gh. 40m. have been received by 

 Mr. Denning from various parts, and they are in verj- fair 

 agreement with each other and with the values given by 

 him for the height, radiant, &:c., in Nature for June 9. 



I'he meteor was seen from Clapham Common passing 

 from a few degrees below the pointers in Ursa Major to 

 a place just north of " The Twins." The trail was a 

 reddish-yellow colour, while the nucleus was a brilliant 

 electric-blue. ' At Loughton, Essex, the meteor was viewed 

 during a portion of its flight over the western sky. The 

 object appeared extraordinarily brilliant, with a blue head 

 and red tail. 



As an instance of the erroneous impressions of nearness 

 occasioned by -the startling lustre of fireballs of this kind, 

 it may be mentioned that the observer at Loughton esti- 

 mated it as seventy yards distant, and thought it must 

 have fallen behind a house near him. Search was made 

 for fragments, but without avail. As a matter of fact, the 

 meteor was more than 100 miles distant. The shower of 

 Scorpiids to which it owed its origin is singularly rich in 

 fireballs in June, and they form probably the debris of 

 some dissevered, periodic comet the materials of which are 

 now distributed into a wide stream. 



Coming Total Eclipses of the Sun. — From Dr. Pio 

 Emanuelli we have received an abstract from the Rivista 

 di Astronomia e Scienze affini (April) in which he discusses 

 in detail the conditions of the total solar eclipses of the 

 sun on May 9, 1910, April 28-29, 1911, and April 17, 1912. 

 The eclipse of 191 1 will have a period of totality of nearly 

 five minutes, and the line of totality will completely 

 traverse the Pacific Ocean ; commencing on the east coast 

 of Australia, it will terminate at a short distance from 

 the west coast of Central America. A small chart given 

 by Dr. Emanuelli shows the path of the shadow touching 

 the islands of Nassau, Samoa, and Tonga. Vavau Island 

 will probably afford the best locale for observations, and 

 at the port of Neiafu, on the south-west coast, totality 

 will last for 3m. 36-8s. with the sun at an altitude of 43°. 

 At Tau, in the Samoan archipelago, totality will endure 

 for 2m. 13s., the altitude being .^1°. The last island to 

 be traversed by the shadow will be Nassau, which is 

 practically an uninhabited desert 1280 metres long and 

 914 metres across : but here the duration of totality will 

 be 4m. los., and the altitude of the sun 57°. 



The New Canals on Mars. — In No. 422 of the Observa- 

 tory (p. 21,:;) M. Jonckheere states that, from observations 

 made at Hem, there can be no doubt as to the reality of 

 the tv.^o new canals recently described by Prof. Lowell. 

 Independent observations by M. Jarry Desloges and him- 

 self disclosed these features, which were carefully studied 

 at the Hem Observatory. 



The OnjECTivE-PRisM Determination of Stellar Veloci- 

 ties. — In No. 4, vol. xxxi.. of the Astrophysical Journal 

 Prof. R. W. W'ood reports further progress in the 1 

 preparation of light-filters for use in the obiective-orismi' 

 radial-velocitv work recently described by Prof. E. CX] 

 Pickering. It will be remembered that by employing a] 

 neodymium-chloride filter. Prof. Pickering introduced a fine 

 absorption line into the spectra to which the stellar linesj 

 could be referred for measurements of velocity in the lin«| 

 of sight. Prof. Wood now finds that the addition 

 erbium chloride introduces another good reference line 

 \ 382, whilst, with isochromatic plates, the narrow inter 

 space between two neodymium bands at \ 5220 might 

 employed. With vapours he believes better results couM 

 be obtained, and he is also experimenting on the mani 

 facture of solid screens bv using a solvent which woul^ 

 solidify, such as styrol. The success attained so far 

 very promising for the final application of this method. 



