HARDWICKE'S SCIENCE-GOSSIP. 



45 



GEOLOGY, &c. 



Geology in Ltverpool.— The " Stony Science" 

 has always flourished in this city, doubtless owing to 

 the presence of such active and well-known geologists 

 as Messrs. Morton, Ricketts, T. M. Reade, Roberts, 

 &c. The Proceedings of the Liverpool Geological 

 Society, part 5, vol. iv., in addition to the President's 

 Address, dealing with the post -tertiary changes of 

 level around the coasts of England and Wales, 

 contains papers (chiefly local, or dealing with the 

 geology of the neighbourhood) by Messrs. G. H. 

 Morton and T. M. Reade. The Transactions of the 

 Liverpool Geological Association is published, price 

 five shillings, in a neat volume of 157 PPm with 

 coloured sections, &c. It contains a vast deal of 

 local geological matter, although many of its papers 

 go farther afield for material. The chief contributors 

 are Messrs. Bramall (President), F. P. Marratt, 

 Beasley, Brennan, Hall, Logeman, T. ]\L Reade, 

 Fox, Miles, George, &c. 



Peculiar Blowhole, near Bideford.— On the 

 ■western bank of the river Torridge, between Bideford 

 and Appledore, there is, just below a rocky cliff, a 

 narrow strip of shaly beach from which, when the 

 tide flows over it, a great number of bubbles burst 

 forth until the water in several places appears to be 

 boiling. I have not been alile to ascertain accurately 

 the composition of the gas in the bubbles, nor what 

 quantity of it was given off", but apparently it was 

 ordinary air and came out at the rate of about five 

 cubic feet per minute. At spring tides the water 

 covers the beach to a depth of three or four feet, 

 and the bubbling will then go on for an hour or 

 more. The only explanation that occurs to me is 

 that there must be some cave with a floor below high 

 water mark, and with one opening through which the 

 rising tide enters, and thus forces out the air above 

 it through another opening so placed in a vertical face 

 of rock that sand and mud cannot be carried in with 

 the receding tide. The tidal water is often heavily 

 charged with mud, and it is certainly remarkable that 

 the cave has not been filled up yet. Apparently this 

 action has been going on for centuries, as there is no 

 historical record of any change in the relative level of 

 land and sea in this neighbourhood. Could any of 

 your readers tell me of similar phenomena ? — Hc7-bcrt 

 G. Spearing. 



The Geologists' Association. — The last number 

 of the " Proceedings " contains the following papers : 

 "On the Drift Deposits at Hunstanton, Norfolk," 

 by B. B. Woodward ; "On Some of the Optical 

 Characters of Minerals," by Professor G. S. Boulger ; 

 " On the Geology of Hunstanton," by W. Whitaker ; 

 " On the Bagshot Series of the London Basin," by 

 the Rev. A. Irving ; " On Probable Glacial Deposits 

 at Ealing," by J. Allen Browne. 



The Droitwich Brine Springs and Salt- 

 FEROUS Marls. — A paper has just lieen read on this 

 important suljject by Mr, C. Parkinson, F.G.S.- 

 The author referred to the effects of the pumping of 

 brine from beneath Droitwich in producing insecurity 

 in the buildings, and proceeded to discuss the possible 

 source of the brine-water system. He referred to 

 the probable existence of extensive beds of rock-salt, 

 lower than the present brine-cavities, towards the 

 north-east of Droitwich — a conclusion which receives 

 support from the deeper borings carried on at the 

 Stoke Works. Full details of these and other 

 recent borings were given by the author. In the 

 discussion which followed, Captain Douglas Gallon 

 said that for every ton of salt at Droitwich 900 

 gallons of water were pumped, a quantity sufficient 

 to exhaust the rainfall of about six square miles, and 

 that whilst formerly the Droitwich brine-springs 

 overflowed at the surface, the brine is now pumped 

 up 200 feet. Pie remarked on the difference of level 

 between the Droitwich and Stoke deposits^the 

 highest bed of rock-salt at Droitwich being about 

 120 feet below mean sea-level and the lowest 170 

 feet ; whilst at Stoke the first bed, which is very 

 thin, is at 170 feet below sea-level, and the lowest 

 yet reached at 300 feet. He suggested the existence 

 of a great fault between Stoke and Droitwich. He 

 thought the question of the existence of deeper 

 supplies of brine at Droitwich a doubtful one. 



NOTES AND QUERIES. 



PlEDGEHOGS.-It would be Well for R. T. V. S. W. 

 to acquire at any rate some knowledge of Natural 

 History before sending queries to a scientific maga- 

 zine. The first one is a fine example of the "scientific 

 method of generalising from observed fact," but it 

 would be well not to forget that generalisations may 

 come under the denomination "rash," especially 

 when founded on insufficient evidence. Moreover 

 "verification" is an important part of this (the 

 scientific) method. I have observed mice not in- 

 frequently in the dwellings of Homo sapiens ; do these 

 ferocious animals devour him? In this and the 

 other matters I would suggest observation, but let 

 R. T. V. S. W. be very careful in making deduc- 

 tions. Moreover, a reference to " Common Objects 

 of the Country" (price only a shilling), in future, 

 would doubtless save this querist much exercise of 

 mind and ingenuity. — J. R. D. 



Early Emergenceof Insects (Science-Gossip, 

 xix. p. 280). It is not unusual for the imagines of 

 Attaais Pcntyi to emerge from the pups the same 

 year. This bombyx is a native of North China, 

 where it is double-brooded. This species passes 

 through its metamorphoses more rapidly under 

 natural conditions than with us ; there is therefore 

 ample time for the development of a second brood, 

 which in this country would hardly be possible. 

 The following notes, relative to A. Ferny i, extracted 

 from my diary may possibly interest Mr. W. Finch. 

 On July 31st, 1875, I received from a friend six pupae 

 of A. Fcruyi. The first, a female, emerged on 



