Walter Keeping — Fossils from Central Wales. 485 



of tlie ground was too slow to be perceived excepting in the water 

 as already mentioned. Whether this was definitely the case or not 

 I am unprepared to say, but certainly these phenomena have their 

 parallel in experiments upon artificially-produced vibration of the 

 earth; as the disturbance radiates from its centre, the waves, if they 

 may be so-called, become longer in their period. 



Surely, when we know as much as this, for us to determine 

 whether these slow pulsatory movements, perhaps emanating from 

 great depths, are taking place in the earth on which we live, is 

 a legitimate investigation. 



As a field from which a rich reward might be gathered by those 

 who are willing to labour in it, and which would yield results of 

 the highest importance to those working at earth tremors, it may be 

 pointed out that almost every inhabitant of a civilized country who 

 dwells within 100 yards of a railway line experiences storms of the 

 most interesting microscopic earthquakes produced by passing trains, 

 every vibration of which might be recorded. Artificial tremors like 

 these, and many others produced in a similar manner, have hitherto 

 only been regarded as the bugbear of practical astronomers and 

 experimental physicists. 



Before the United States Naval Observatory at Washington was 

 erected Professor H. M. Paul was deputed to make a tremor survey, 

 and to discover stable ground. Sir George Airy, who was troubled 

 with the tremors of Greenwich Hill, has left a record of his battles 

 with these obtruders in apparatus designed to eat them up. 



Lieutenant-Colonel Palmer, when observing the transit of Venus 

 in New Zealand in 1874, intrenched himself against the enemy by 

 digging pits. Captain Kater, with his pendulums, rather than fight 

 the foe, fled out of London. 



All that science has usually done for artificially-produced tremors 

 has been to destroy them, and, if not successful, to bury them with 

 imprecations. 



How far a set of diagrams which tremors like these could be made 

 to draw would be supplemental to the work which will be accom- 

 plished sooner or later by those who undertake the observation of 

 natural tremoi's it is needless to dilate upon. With telescopes and 

 other instruments we are measuring the motions of the heavenly 

 bodies; with thermometers, barometers, and other instruments we 

 are perpetually examining the temperature and pressure of the 

 atmosphere ; with tide gauges we note the rise and fall of the ocean. 

 Surely after this it becomes imperative that we should pay some 

 attention to<the movements of the land on which we dwell. 



II. — On some Eemains of Plants, Foraminifera and Annelida, 



IN THE Silurian Kocks of Central Wales. 



By Waltek Keeping, M.A., F.G.S., Keeper of the York Museum. 



(PLATE XI.) 



ry^WO years ago if a Palasontologist had been asked to mention 



\ a region in Britain most barren of fossils, he might well have 



ected that great area of Central Wales which is marked by a 



