October 2, 1890] 



NATURE 



555 



r 



had not given satisfaction, and that at considerable expense iron 

 axles were to be substituted for them. Our contemporary 

 observes that questions have, naturally enough, been asked, 

 and publishes Sir A. M. Rendel's reply : — " I originally," he 

 says, " recommended the use of steel for axles on the Bombay, 

 Baroda, and Central India metre gauge, because I thought that 

 steel was not only better than iron, but because its price was not 

 more than half that of the class of iron suited for axles. I was 

 further moved to do so by an opinion that, whilst steel was im- 

 proving in quality, and daily taking the place of the best classes 

 of iron, the quality of those classes of iron must deteriorate, 

 because the price obtainable for them must diminish. In re- 

 spect to the relative price of steel and iron, I was quite right ; 

 in respect to their relative suitability for axles, I have been 

 wrong, or, at any rate, premature. Commercial steel, when used 

 in axles, seems subject to deterioration, which makes it very 

 brittle after a few years^ wear. The consequence is that we 

 must do now what we should certainly have done at first, had 

 all the facts been then before us — I mean, we must substitute 

 iron for steel. It being also desired that our waggon loads 

 should be increased, it has been found necessary to increase the 

 size of our axles, and their weight in iron is now 231 lbs., 

 instead of 198 lbs. in steel ; and their present cost is £2(is., 

 instead of about £1 2s. 6d. Had we originally supplied the 

 large iron axles, capital would have been chained, for every 

 such axle supplied, the sum of ;^2 6s. or thereabouts, instead of 

 £1 2s. 6d., and I can see no reason why, because we attempted 

 an economy in the first instance, which experience has proved to 

 be impracticable, capital should escape the larger charge now. 

 It appears to me indisputable that the difference between the 

 cost of the axles originally supplied and those now sent out 

 should be charged to capital and not to revenue." The italics 

 in this quotation are those of the Engineer, and the state- 

 ment is a grave charge against steel, and one that the steel 

 manufacturers will no doubt combat strongly. The Engineer 

 does not tell us where these metre gauge axles have usually 

 failed, and it is therefore difficult to find a reason for the whole- 

 sale rejection of steel as a suitable material for axles, always 

 bearing in mind the general use of this material in this country 

 for that purpose, with the greater mileage run with steel axles, 

 be they crank or straight axles, over that obtainable from iron 

 axles. It is to be hoped that the matter will be thoroughly 

 thrashed out. The question of manufacture must not be over- 

 looked. Steel rails occasionally fail at the ends owing to in- 

 sufficient "crop" being cut off the rolled rail, i.e. the steel 

 is not considered sound for about 3 feet from each end of the 

 rail as it leaves the rolls, and is therefore usually rejected as 

 " crop ends." If these axles are rolled ones, probably this 

 might explain the failures, if they usually took place at the ends 

 and not in the middles. 



The autumn series of science lectures at the Royal Victoria 

 Hall began on Tuesday with a lecture on "Nebulae," by Mr. J. 

 D, McClure. The arrangements for lectures during the month 

 of October are as follows : — October 7, "The Sun," by J. D. 

 McClure ; October 14, " Bees as Florists and Fruit Producers," 

 by Rev. Prof. Cheshire ; October 21, " The Colours of Animals 

 and their Uses," by Dr. \V. D. Halliburton ; October 28, 

 " Mountaineering," by H. G. Willink. 



The additions to the Zoological Society's Gardens during the 

 past week include a Brown Bear {Ursus arctos <J ) from 

 Russia, presented by Mr. G. W. Robinson ; a Golden Eagle 

 {Aquila chrysaetus ? ) from the Rocky Mountains, Wyoming, 

 U.S.A., presented by Mr. Percy Cooper; two Common 

 Squirrels {Sciurus vulgaris), British, a Reticulated Python 

 {Python reticulata) from Siam, purchased ; five Viperine Snakes 

 ( Tropidonotus viperinus), born in the Gardens. 

 NO. 1092, VOL. 42] 



OUR ASTRONOMICAL COLUMN. 

 Objects for the Spectroscope. 



Sidereal Time at Greenwich at 10 p.m. on October 2 

 22h. 46m. i6s. 



Remarks. 



(1) In the spectrum of this nebula Dr. Huggins has recorded 

 only the chief nebula line near A. 500. It is remarkable that 

 Herschel describes it as easily resolvable, and if this be correct 

 the nebula must be regarded as a cluster of nebulous stars. 

 This important result is well worth checking, both by telescopic 

 and spectroscopic observations. 



(2) This nebula is described as "considerably bright; con- 

 siderably large ; little elongated ; gradually much brighter in 

 the middle; mottled as if with stars." The spectrum of the 

 nebula is rather vaguely described by Dr. Huggins as follows r 

 "The spectrum does not consist of one or two lines only; I 

 believe it is continuous." The doubt should be removed by a 

 more definite observation. 



(3) The spectrum of this star is a very fine one of Group II. 

 The dark bands, however, are by no means so strongly deve- 

 loped as they are in a Herculis or Mira, but still they are well 

 marked, and, in addition, the spectrum abounds with lines. The 

 relative feebleness of the bands, and the presence of so many 

 lines, indicates that the star is well advanced in condensation, 

 and this is further confirmed by my own observation of the com- 

 paratively feeble bright flutings of carbon. Most of the lines 

 are identical with those seen in Aldebaran. D is partly hidden 

 by a dark fluting, but lines in other places stand out promi- 

 nently. They are not quite like those seen in the solar spec- 

 trum, and hence the spectrum of the star is one from which 

 useful information relative to the criteria between Groups III. 

 and V. may be derived. 



(4) Prof. Pickering has found by photography that the spec- 

 trum of this star contains bright lines. Vogel, however, de- 

 scribes the spectrum as a well-marked one of the solar type, and 

 makes no mention of bright lines. In my own observations of 

 the star I found the dark lines characteristic of the spectrum of 

 a star like the sun, but detected no bright ones. It is quite 

 possible, therefore, that the bright lines are not always visible, 

 and the spectrum should be examined with reference to a possible 

 periodicity. 



(5) According to the observations of Konkoly, this star has a 

 well-marked spectrum of the solar type, but Gothard and Vogel 

 describe it as one of Group IV. My own observations confirm 

 those of Vogel. 



(6) A star of Group IV. 



(7) This faint star has a spectrum of Group VI. , and Duner 

 states that the dark carbon band which separates the green and 

 yellow zones is wider than he has seen it in any other star. The 

 blue zone is scarcely perceptible. It seems as if this is a star 

 which has cooled down until it is almost non-luminous, and the 

 observation is important as indicating to a certain extent what 

 the spectrum will be at the last stage of visibility. It appears 

 that the carbon absorption intensifies until finally all the 

 remaining light is absorbed. A. Fowler. 



The Telluric Spectrum.— The current number of Compte 

 rendus (September 22) contains an account of the expedition 

 lately made to the summit of Mont Blanc by M. Janssen, for the 

 purpose of observing the spectrum of the sun from an elevated 

 station. Two years ago M. Janssen ascended Mont Blanc as far 

 as the Grands-Mulets, a station having an altitude of 3050 metres. 

 The spectroscopic observations then made showed that a diminu- 

 tion took place in the intensity of the groups of lines A, B, and 

 a, due to the action of the oxygen in the atmosphere, and indi- 

 cated very definitely that at the limits of our atmosphere these 

 groups would disappear. To confirm these results it was re- 

 solved this year to repeat the?observations at a greater elevation,. 



