September 6, 1900] 



NA TURE 



437 



secured by very dift'erent means in two plants of the same 

 genus, and so very much ali^e in all other particulars. 



Hobart, July 25. Henry J. Coi.bourn. 



Electricity direct from Coal. 



With reference to the announcement made in the Daily 

 Mail of September i, that Thomas A. Edison had com- 

 pleted a machine for the generation of electric power direct 

 from coal without the use of engines or dynamos, may I ask 

 you to reprint a few lines from an article on electric traction 

 I wrote for you, and which you published on April 12, 1894 ? 



" Before electric traction can be employed on a very large 

 scale, we must possess a means of producing the electricity 

 on the spot and at the time it has to be used, or, in other 

 words, we must possess a battery in which the energy of coal 

 can be transformed directly into electric current, so that we 

 may do without storage batteries in which to carry electric 

 energy about, or heavy copper conductors through which to 

 convey it at moderately low tension from the spot where it is 

 produced to where it is used, or light aerial conductors through 

 which to convey it at high tension. 



" How long we shall be without this, or how many minds 

 are engaged in the solution of this or some such problem, we 

 know not, but the moment it is solved, and solved doubtless 

 it will be, there will be such a transformation scene in the 

 industrial applications of electricity as one can hardly con- 

 ceive. It would mean that for almost all purposes except 

 those in which heating is required electricity would or could 

 be used. An electric light-producing battery in every house, 

 quite independently of any mains in the streets ; an electric 

 power-producing battery to carry us whither we would on 

 rail's or on the streets; and in every house to put an end to 

 all the evils attendant on crowded factories and workshops, in 

 crowded streets and towns ; such and other advantages would 

 result from turning electricity from a servant into a master, 

 from a mere transformer of energy into a source of energy." 



E. F. Bamber. 



48 St. James's Square, W., September 3. 



Artificial Deformations of Heads, and some Customs 

 connected with Polyandry, 



With reference to your note on M. Charles de Ujfalvy's recent 

 article in F Anthropolo^^ie (p. 323, ante), I may be allowed to 

 call your attention to the ancient Korean practice of artificially 

 deforming their heads, which was apparently similar to the 

 method adopted by the Huns as well as the Huna kings of 

 India. Thus, the Chinese "History of the Later Han 

 Dynasty," written in the fifth century, sub. " Eastern Bar- 

 barians," says : "The people of Ma-Kan (in the south-western 

 part of the Korean peninsula) wish their heads flat ; so the 

 head of every child just born they compress with stone to 

 deform it." 



The special horned head-dresses worn by the polyandric 

 women of the White Huns put in mind the old Japanese usages, 

 described by Fujioka and Hirade in their " History of the 

 Japanese Customs and Manners," Tokio, 1897, vol. i. p. 169 : 

 " In the festival of the god of Tsukuma, every woman had to 

 go in procession after the holy sedan-chair, with a number of 

 pans on her head proportionate to her immoralities. In the 

 temple of Usaka, while the priest was praying in a feast-day, 

 every woman was scourged on similar principles." 



KUMAGUSU MiNAKATA. 



I Crescent Place, South Kensington, August 11. 



Huxley and his Work. 



O.N p. 13 of " One Hundred and One Great Writers," issued 

 by the Standatd, and presumably edited by Dr. Garnelt, occurs 

 the following remarkable account of Huxley and his work. 

 " Huxley's work is that of the populariser, the man 'u<ho makes 

 few original contributions to science or thought, but states the 

 discoveries of others better than they could have stated them 

 themselves." Comment is needless. F. W. Henkel. 



Markree Observatory, Collooney, Ireland, August 23. 



THE CAUSES OF FRACTURE OF STEEL 

 RAILS. 

 "VITHEN the down Scotch express was running through' 

 * ' St. Neots station, on the Great Northern Railway,, 

 on December 10, 1895, a rail broke into seventeen pieces, 

 part of the train left the metals, and a serious accident 

 resulted. Several features of the report on the mishap, 

 drawn up in the ordinary course by the late Sir Francis 

 Marindin, might well have occasioned deep thought, 

 notably the conclusion that the first fracture of the rait, 

 took place over a chair at a minute induced flaw, which- 

 did not exist when the rail was manufactured. 



The whole report, however, is suggestive rather than- 

 explanatory, and the result was the appointment by the 

 Boardof Trade of a committee to investigate the question 

 of the loss of strength of steel rails caused by prolonged 

 use. The committee was a very strong one, and con- 

 tained some distinguished steel manufacturers, engineers, 

 metallurgists and chemists. They collected a vast amount 

 of information, much of it apparently considered unsuit- 

 able for publication, and made long series of experiments, 

 many of them, judging from the report, more easily made 

 than their results explained. 



Finally, after four years' work, they have issued a re- 

 port with the satisfactory featt^ire that practically no- 

 change is recommended to be" made in the mode 0$ 

 management of the permanent way by the railway 

 companies. 



Pearlite ^^ 



Steel rail. X 850 d. Showing pearlite and ferrite. 



Nevertheless, although no legislation seems likely ;to- 

 result from the labours of the committee, the evidence- 

 that has been collected and published in the appendices 

 to the report is of great scientific interest. The experi- 

 mental work that was undertaken was divided among 

 the members of the committee. A number of rails found' 

 broken on the road, or discarded as worn out, were 

 selected for examination. Prof. Unwin took charge of 

 the tests on their hardness, tensile strength and bending 

 strain, and Mr. Windsor Richards of those on their re- 

 sistance to the shock of falling weights ; Sir Willian> 

 Roberts-Austen made inicrographical examination of the 

 rails, and Dr. Thorpe analysed them. Sir Lothian Belk 

 includes in his comprehensive memorandum details of 

 a number of mechanical tests on rails, and Prof. Dunstaiv 

 gives an interesting account of the effects of atmospheric 

 corrosion. 



Interest naturally centred around the St. Neots raiL 

 It was found to be of ordinary composition, and the 

 mechanical tests applied to it showed that the steel was- 

 of variable, but, on the whole, of good quality. It was 

 only on microscopic exainination that the extraordinary 

 character of the rail became evident. Good rail steel, 

 according to Sir W. Roberts-Austen, consists of "fernte,"' 

 or iron free* from carbon, and " pearlite," which is a 

 mixture of alternate bands of ferrite and "cementite" 

 (the carbide corresponding to the formula FegC). The 

 structure is shown m Fig. i, a reproduction of a micro- 



NO. 1 610, VOL. 62] 



