Ski'Thmukk 3, 1896J 



NA TURE 



'^'5 



Decemlier 29, 1881 ; May S, 1SS4; and one on "ACual-dust 

 KxpliKicin," February 17, 1887. 



During the ten years ending in 18S5, I was engaged from 

 linie lo time in carrying out experiments with coal-dust: first, 

 with apparatus provided by the Cllamorgan Coal Company, 

 Limited, and erected at their Llwynypia Colliery ; secondly, 

 with apparatus purchased by means of (lovernmenl grants 

 obtained through the Royal Society ; and, thirdly, with 

 apparatus belonging to the Royal Commission on Accidents in 

 Mines, 



Before the accounts of my earlier investigations, and the 

 conclusions founded upon them had appeared, the Inspectors of 

 Mines and other mining experts were practically unanimous in 

 attributing the cause of every great colliery explosion to the 

 sudden outburst of a large volume of fire-damp which was 

 supposed to have flooded the workings, become mixed with the 

 air, and, on being ignited in one way or another, produced the 

 various phenomena subsequently observed. This explanation 

 was accepted everywhere as the only one possible ; it was 

 recorded in the official reports of the Inspectors of Mines, and 

 they, as well as the experts of that generation, were irretrievably 

 committed to it. 



There was not, figuratively speaking, a ripple of dissent from 

 this mode of explanation upon the placid surface of mining 

 opinion at the moment the coal-dust theory was launched 

 upon it. 



.\t lirst the new theory was ignored ; then it was scouted ; 

 then it was subjected to scathing criticism ; then it was taken 

 up in a tentative manner by some of the younger and bolder 

 men : and, lastly, when it was found to be making serious 

 headw.iy, one of the more adventurous spirits suddenly dis- 

 covered that it was not new after all, for had not Faraday and 

 Lyell and certain French engineers been its real authors? 



Following my lead, first a joint paper, by Messrs. Hall and 

 Clark, was contributed to the North of England Institute, in 

 May 1876, then another by Messrs. Marrecco and Morrison, in 

 1878, all of whom, with the exception of Mr. Clark, had 

 previously corresponded with me on the subject of explosions ; 

 finally, in the year 1879. after the publication of my articles on 

 " Coal-dust Explosions" in Iron, and during the next few years 

 afterwards, a very great army of investigators, headed by 

 Government Commissions in England, France, Prussia, Austria 

 and Saxony, and including the Messrs. Atkinson, entered the 

 field. 



Some of these investigators contented themselves with 

 criticism pure and simple ; others, of whom many had neither 

 aptitude nor training for the work, made experiments with small 

 and imperfect apparatus, and, as a consequence, obtained only 

 negative results ; still others were carried away by the side 

 issues ; and only a few, such as the Prussian and Austrian 

 Commissions, and Messrs. Hall and Atkinson, H.M. Inspectors 

 of Mines, did really good and substantial work of an enduring 

 kind. 



The facts and conclu.sions recorded in my earlier papers were 

 freely drawn upon : by some they were generously acknowledged ; 

 by others they were first denounced and then assimilated ; by 

 others they were adopted without acknowledgment ; while some 

 of my experiments, and notably my investigations into the 

 nature of the Fire-damp Cap (Proc. Koy. Soc, March 2, 

 1876), were repeated with some variations and described as if 

 they were original. 



A tlood of literature was now poured upon the mining world 

 from every side, embodying opinions ol the most conflicting and 

 mystifying character, such as — a mixture of coal-dust and air 

 may lake fire but it cannot explode ; coal-dust can only carry 

 flame from one accumulation of fire-damp to another ; a coal- 

 dust flame cannot extend throughout the workings of a mine in 

 tlie entire absence of fire-damp ; a small proportion of fire-damp 

 must always be present in the air when an explosion takes 

 place ; some kinds of coal-dust are more inflammable than 

 others — and so on, so that amid the din and hurlyburly of the 

 strife the main question of how to put an end to great explosions 

 was almost lost sight of. 



Rut the scene of each successive explosion when viewed under 

 the new light served gradually to dispel the illusions which had 

 fascinated the majority of the investigators for years ; and thus 

 it has come to pass that the new generation of Inspectors of 

 Mines, and those who have been associated with them in 

 investigaiing the phenomena of explosions, have become con- 



NO. 1401, VOL. 54] 



vinced, I believe almost to a man, of the soundness of the coal- 

 dust theory ; and that the struggle of contending factions, which 

 was at its height ten or twelve years ago, has gradually subsided, 

 leaving us face to face with a work which still remains to be 

 done, namely, to render the occurrence of a great colliery 

 explosion impossible in the future. > 



Into the consideration of that problem I do not propose to 

 enter on the present occasion, as I have lately done so in con- 

 siderable detail in the pages of the Daily Chronicle of June 24 

 of the present year. W. Galloway. 



Cardifi", July 17. 



THE AUGUST METEOR SHOWER, 1896. 



'"PHE moon being absent from the nocturnal sky 

 -'■ during the recent return of the Perseids, encouraged 

 the hope that the shower would be somewhat brilliant ; 

 but the weather is an clement of great importance in 

 such observations, and it was by no means favourable 

 during the late display. In the south of England several 

 nights were partly clear near the important time, and on 

 August 10 the firmament at Bristol was almost free from 

 dark cloud ; but the sky was hazy and the stars dim, so 

 that only the brighter meteors were observed. 



On August 6, during an hour's watch before loh. 50m., 

 I counted twelve meteors, of which seven were Perseids, 

 with a radiant at 42° + 56". The shower was evidently 

 pretty active, and the meteors fairly bright, but clouds 

 overspread the sky before iih., and prevented further 

 observation. 



On August 7, in an hour's watch preceding llh., nine 

 meteors were seen, including about six Perseids, but clouds 

 were very prevalent during the whole time, and effectually 

 obliterated the stars at a later period of the night. 



On August 10 the weather was fine, but the atmosphere 

 was not transparent enough to be considered favourable 

 for meteoric work. Haze was spread over the sky, and 

 the fainter stars were obscured. Near the horizon 

 nothing could be discerned. I began watching for 

 meteors at about gh. 50m. and continued until i4h. 15m. 

 During this interval of 4h. 25m. I saw ninety-eight shoot- 

 ing-stars, of which sixty-nine were Perseids, and twenty- 

 nine belonged to the minor, contemporary showers of the 

 period. I registered the apparent paths of a considerable 

 number of the meteors seen, and while engaged in doing 

 this, must have missed many others which appeared 

 while my attention was diverted from the sky. It is 

 probable that fully one hundred and fifty meteors would 

 have been counted by an observer watching the sky 

 uninterruptedly during the period mentioned. Nearly all 

 the Perseids left streaks, but the meteors generally were 

 not very bright. The radiant point was tolerably well 

 defined, but it was certainly not so definitely marked as 

 I have sometimes seen it. I determined it at different 

 times of the night as follows : — 



9 50 to II o 



II o to 1 1 30 



II 30 to 13 o 



13 o to 13 45 



13 45 to 14 15 



43 + 57 



44 + 57 

 46-1-57 



45 + 59 

 46 -^ 57 



The mean of the five positions being at 45'' -I- 57 ', which 

 coincides with the usual place of the radiant on August 10. 



On August 1 1 the heavens were overcast, but on August 

 12 a beautifully clear sky enabled me to resume observ- 

 ations. I saw fourteen meteors in about an hour and a 

 quarter before 1 ih. 15m., and of these seven belonged to 

 the Perseid shower. The radiant was at 46° -(- 57°, but 

 it was imperfectly defined. 



On August 14 the firmament was again dear, and I 

 saw nine meteors in three-quarters of an hour before 



