228 DR. CHARLES DAVISON ON TIIE [May I904, 



any of the men, although a ' dreadful roaring noise ' was heard. As 

 the mine must be in the immediate neighbourhood of the north- 

 eastern focus, and especially of its marginal regions, it is probable 

 that the sound overpowered all other sensations. 



(3) In several cases, the sound appeared to be more overhead 

 than below. At Clay Cross, according to one observer, the sound 

 was noticed ' more as in the roof than on the floor ' ; according to 

 another, there was ' a rumbling noise above, as though a train was 

 passing over/ In the Manners Colliery, near Ilkeston, at a depth 

 of about 400 yards, the sound is described as like that of a train 

 passing close overhead, while some of the men thought that it was 

 caused by a break in the overlying strata. At Pilsley, near Clay 

 Cross, the rumbling resembled that of a train of trucks passing over 

 the workings. Lastly, at Swadlincote, near Burton-on-Trent, men 

 working in the Eureka seam at a depth of 400 yards were alarmed 

 by a rumbling noise ' passing overhead, like a railway-train passing 

 over a wooden bridge ' ; others in the Kilburn seam, 470 yards below 

 the surface, heard a heavy rumbling noise, ' as though the stone- 

 head was falling in,' which seemed to pass over their heads and die 

 away in the distance. 1 



(4) Mr. G. S. Bragge, who kindly communicated the last account, 

 informs me that the rumbling noise was also heard in some cases 

 in the Woodfield seam, 350 yards from the surface, but no notice 

 was taken of it. In the workings of the Little Coal, at a depth of 

 about 220 yards, he was unable to find that any unusual noise was 

 heard at all. It would seem, then, that the intensity of the sound 

 increased with the depth of the workings. 



Effect on Underground Water. 



The only observation under this heading that I possess is one 

 communicated to me by Mr. Arnold-Bemrose, from Mr. T. Webster 

 at Hognaston, a village which lies about a mile east of the centre, 

 and probably not far from the line of the earthquake-fault. Shortly 

 after the earthquake, the water of the village-well was found to be 

 of a milky colour. Mr. Webster then emptied the well three times, 

 and saw the water bubbling out of the springs at the bottom quite 

 thick, as if with powdered lime. It remained so for two or three 

 days before it returned to its normal clearness, after which a white 

 sediment remained at the bottom for a few weeks. Mr. Webster adds 

 that he has known the well for 35 years, and that neither he nor 

 the oldest inhabitant can remember a similar occurrence. Whether 

 the sediment was a result of the fault-slip that caused the earthquake, 

 or merely a secondary effect of the shock itself, is doubtful, though 



1 A similar observation was made in amine at Ashover, near Matlock, during 

 the earthquake of November 18th, 1795. The men at work heard 'a rushing 

 rumbling kind of noise, which appeared to be at a distance, and to come nearer 

 and nearer, until it seemed to pass over them, and die away.' The position of 

 the epicentre is unknown, but it was probably not very distant, for several 

 chimneys were thrown down at Ashover, Phil. Trans. Roy. Soc. vol. lxxxvi 

 (179(>)p. 359. 



