526 Correspondence — J. JR. Dakyns — T. E. Knightley. 



in second-hand science. As it is, I content myself with remarking 

 that the maxim " Verbum sat sapienti " has only a very limited 

 application in scientific matters, for there a diet of words is both 

 innutritions and flatulent. But as he evidently loves " wise saws " 

 I will add another to his store, " Words are the counters of wise 

 men and the money of fools." T. G. Bonney. 



INTEUSIVE IGNEOUS ROCKS IN IRELAND. 



Sir, — With reference to the interesting paper on " Intrusive, 

 Tuff-like, Igneous Eocks and Breccias in Ireland," by Messrs. 

 Kilroe and M'Henry, published in the August number of the 

 Q.J.G.S., it is noteworthy that there are in the neighbourhood of 

 Snowdon several instances of intrusive rocks of so fragmentary 

 and brecciated a character as to resemble volcanic agglomerates. 

 Such is the case in part with the diabase occurring in Cwm Llan, 

 S.S.E. from the summit of Snowdon. Other instances of this 

 character that I have observed are a small boss of brecciated diabase 

 at the base of the felstone of Cribiau, near Bwlch Ehediad, and 

 another, also of a fragmentary character, amidst the felsitic rocks on 

 the south-east side of Llyn Gwynant. Somewhat similar too is the 

 greenstone on Glyder Fawr, which Eamsay in his memoir on North 

 Wales describes as a " great vesicular, rubbly-looking patch." 



J. E. Dakyns. 

 Snowdon Vietv, Nant Gwynant, Beddgelert. 

 October 10, 1901. 



EBBING AND FLOWING WELLS AND SPRINGS. 



Sir, — Some time back you were good enough to print a com- 

 munication from me on the ebbing and flowing well between 

 Buxton and Castleton in Derbyshire. In the Illustrazione Popolare 

 of August 18th of this year is a paper on a phenomenon of the 

 Lago di Garda of kindred character, of which I submit a substantial 

 translation. 



" The Lago di Garda is one of the largest lakes in Italy, admired 

 for the fertility of the country that surrounds and for the beauty of 

 the gardens that adorn its shores. There happens in these days 

 a phenomenon that impresses the surrounding population ; a flux 

 of thirty centimetres of height every forty minutes is observed, 

 according to the boatmen. Many newspaper readers wish to explain 

 it as a result of volcanic action. 



" The phenomenon may have a volcanic origin, since from the 

 beginning of 1800 Count Bettoni, a studious naturalist, had to 

 verify in the lake a species of flux and reflux, not perilous but 

 irregular and inconstant ; and not only is it in the Lago di Garda 

 observed, but in the lake of Geneva the water rises and falls in 

 a notable manner. 



" The phenomenon cannot be attributed to the action of the sun 

 and moon, since the action of these two stars should produce a rise 

 and fall regularly as in the level of the sea. 



