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SCIENTIFIC NEV^^S. 



[July 1st, 1887. 



Committes had collected and weighed the results of experience, and 

 the views and opinions of miners, mine-managers, and scientific 

 experts, and as a result much improvement had taken place in 

 the working, management, and supervision of mines. But 

 within the last ten years it had been warmly maintained, by 

 competent authority, tliat the benefits which should accrue from 

 the existing laws were far from being fully realised, while further 

 and more stringent legislation was urgently needed in several 

 directions. In Parliamentary debates great stress had been laid 

 upon the lamentable loss of life due to explosions in mines, but 

 It was scarcely realised that certain causes of accident, which 

 attracted but little public attention, gave rise year after year to 

 a proportion of deaths far exceeding that due to explosions. In 

 support of these opinions, the author submitted a table, compiled 

 from the annual reports of the mine-inspectors for the years 1875 

 to 1885 inclusive, from wliich it appeared that, out of 12,315 

 deaths, only 2357 per cent, arose from explosions of firedamp, 

 while 4077 per cent, were due to falls of roof and sides of mine- 

 workings, the remaining 3 5 '66 per cent, being the results of mis- 

 cellaneous accidents. Moreover, the percentage of deaths due 

 to explosions was very fluctuating, specially heavy mortality 

 having been caused by particularly calamitous explosions in 

 certain years ; while, on the other hand, the loss of life caused 

 by falls of roof and sides was not only almost always higher than 

 that due to explosions, but it was also nearly constant. As an 

 instance of the smaller classes of preventible accidents m mines, 

 due to modes of working, reference was made to the custom 

 prevailing in South Wales, of allowing boys to run in advance 

 of the horses and trams used for haulage for the purpose of 

 opening and closing the air-doors. It had been frequently 

 pointed out that the danger arising from this custom would be 

 obviated if boys were stationed at the air-doors, instead of being 

 allowed to run with the trams. The class of accidents con- 

 nected with the shafts of a mine appeared to have been more 

 successfully grappled with. 



The sudden and violent escape of gas accumulated locally 

 under great pressure was also considered, reference being made 

 to various recorded outbursts of gas in England, and to the 

 remarkable occurrence of natural gas in the petroleum districts 

 of the United States and of the Caucasus. The possibility of 

 taking measures for facilitating the comparatively gradual 

 escape of firedamp from gas-bearing strata, so as to relieve the 

 pressure, had received much serious attention. The driving of 

 bore-holes into the coal in advance of the working face had been 

 attended with good results. Recourse had also been had to 

 bore-holes driven into gas-bearing strata contiguous to mine- 

 workings ; but the time and cost of carrying out such operations, 

 to any useful extent in localities where such strata were at a 

 distance from the workings, precluded any considerable exten- 

 sion of this system. 



The careful examination into the effects produced by explo- 

 sions in mines had led to a very general realisation of an 

 important element of danger, additional to, and possibly some- 

 times independent of, the presence of firedamp in the atmos- 

 phere of a mine. The discussion of this branch of the subject, 

 and of those relating to the employment of explosives in mines, 

 and the illumination of mine-workings, was reserved for the 

 second part of this paper, not then read. 



THE GEOLOGICAL SOCIETY. 



A MEETING of this society was held on May 25th, Prof. J. 

 W. Judd, F.R.S., president, in the chair. The following 

 communications were read ; — 



I. " On the Remains of Fishes from the Keuper of Warwick 

 and Nottingham." By E. T. Newton, Esq., F.G.S. ; with Notes 

 on their Mode of Occurrence, by the Rev. P. B. Brodie, M.A., 

 F.G.S., and E. Wilson, Esq., F.G.S. This paper gave an account 

 of two series of fossil fishes which have been discovered in 

 British Triassic strata. The specimens are very fragmentary, 

 but the rarity of Ganoid fish remains in the English Trias lends 

 considerable interest to these discoveries. The first series 

 noticed were obtained by the Rev. P. B. Brodie in the Upper 

 Keuper of Shrewby, and consist of some half-dozen portions of 

 fish, all small and much broken. The characters of the scales 

 and the positions of the fins, together with as much of the forms 

 as can be made out, point to their belonging to the genus 

 Setnionotiis. The second series were obtained by Mr. E. Wil- 



son, F.G.S., of the Bristol Museum, from Keuper Beds, near 

 Nottingham. A large number of specimens were in this case 

 collected ; but all of them are too mucia broken and crushed out 

 of shape to allow anything very definite to be said about them. 

 Some of these also appear to be Seviioiiotus ; they agree in size, 

 as well as in some other particulars, with the Shrewby fishes, 

 and may perhaps belong to the same species ; but others, on ac- 

 count of their strongly heterocercal tail and ornamented scales, 

 seem to belong to the Palaeoniscidse. The presence of a third 

 form among these Nottingham fishes is indicated by masses of 

 larger scales. The Rev. P. B. Brodie and Mr. Ed. Wilson each 

 appended notes on the Triassic Beds from which the fishes were 

 obtained. 



2. " Considerations on the Date, Duration, and Conditions of 

 the Glacial Period with reference to the Antiquity of Man." By 

 Prof Joseph Prestwich, M.A., F.R.S., F.G.S. After showing 

 how the discoveries in the valley of the Somme and elsewhere, 

 twenty-eight years ago, led geologists who had previously been 

 disposed to restrict the age of man, to exaggerate the period 

 during which the human race had existed, the author proceeded 

 to discuss the views of Dr. Croll on the date of the Glacial epoch. 

 Dr. Croll, who had at first referred this to an earlier phase of 

 orbital eccentricity, commencing 980,000 years ago, subsequently 

 regarded it as coinciding with a minor period of eccentricity 

 that commenced 240,000 and terminated 80,000 years since. 

 This last estimate was chiefly supported by the amount of 

 denudation that had subsequently taken place. The efficacy of 

 the increased eccentricity of the earth's orbit in producing the 

 cold of the Glacial epoch was shown to be very doubtful ; for as 

 similar changes in the eccentricity had occurred 165 times in the 

 last lOo millions of years, there must have been many glacial 

 epochs in geological times, several of them much more severe than 

 that of the Pleistocene period. But of such glacial epochs there 

 was no valid evidence. Another inference from Dr. Croll's 

 theories, that each glacial epoch consisted of a succession of 

 alternating cold and warm or inter-glacial phases was also ques- 

 tioned, such alternations as had been indicated having probably 

 been due to changes in the distribution of land and water, not to 

 cosmical causes. The time requisite for such inter-glacial periods, 

 as were supported by geological evidence, was more probably 

 hundreds than thousand of years. Recent observations in Green- 

 land by Professor Helland, Mr. V. Steenstrup, and Dr. Rink, had 

 shown that the movement of ice in large quantities was much 

 more rapid, and consequently the denudation produced much 

 greater than was formerly supposed. The average rate of pro- 

 gress in several of the large iceberg-producing glaciers in Green- 

 land had been found to be thirty-six feet daily. Applying these 

 data and the probable accumulation of ice due to the rainfall 

 and condensation to the determination of the time necessary for 

 the formation of the ice-sheet, the author was disposed to limit 

 the duration of the Glacial epoch to from 15,000 to 20,000 years, 

 including in this estimate the time during which the cold was 

 increasing, or pre-glacial time, and that during which the cold 

 was diminishing, or post-glacial time. 



THE SOCIETY OF CHEMICAL INDUSTRY. 



BACTERIOLOGICAL RESEARCH AND WATER SUPPLY. 



DR. PERCY FRANKLAND read a paper on the above sub- 

 ject, in continuation of experiments which he had made 

 known to the society eighteen months previously, since which 

 time he had been conducting a monthly examination of waters 

 for the Local Government Board. He had tested the unfiltered 

 waters as taken from the points of supply, and also in the con- 

 dition supplied by the companies, giving the number of microbes 

 present in each case. Contrary to what might be expected, the 

 organisms are most numerous in the water in the winter months, 

 perhaps because in summer the rivers are fed more by spring 

 water, and less by surface and drainage waters. In the winter, 

 with increase of rain, the microbes increase also ; but in every 

 case the number of microbes was less after filtering. He gave 

 many figures in support of his statements, and mentioned that 

 the companies did not all proceed upon the same lines in their 

 filtering operations, and why some succeeded better than others 

 was a subject for careful study. No conclusion as to the relative 

 excellence of the waters could be drawn from the figures he had 

 given ; they merely showed the probable fate of any dangerous 

 organisms which might be present at the unfiltered source. 



