19I-. Irish Societies. 23 



In forty years the sand had completely buried the place, only the chimney 

 of the school showing above it. At Horn Head part of the road is com- 

 pletely buried, and the sand has drifted up the hill to an altitude of 350 

 feet. It has buried many large fields once cultivated here. In south-west 

 Mayo the inhabitants near the shore have great difficulty in keeping the 

 sand from travelling inland. At Dooaghty, west Mayo, great changes have 

 taken place in the last 50 years. Kinahan, in " Geology of Ireland," states 

 that near Broadhaven the Bent was burnt off the sand-hills, and the sand 

 commenced to travel up the hill to the north-east. In 1878 it had crept 

 up 700 feet, destroying all before it, and the occupiers had to move to 

 the other side of the hill. In Omey Island, off the Galway coast, the sand 

 has covered up a village, and the natives now come out of holes like 

 rabbits out of a burrow. In Inishmore, Aran, and at Errismore, sands are 

 travelling southward out to sea. At Arklow the great dunes have almost 

 disappeared. At Culbin, in Scotland, blown sands overwhelmed an estate 

 that was rented at ;^6,ooo per annum. In the Kurische Nehrung, a long 

 narrow sandy neck of land on the north coast of Germany, blowing sands 

 buried, and then left free, a church. The Merthyr Mawr sand-hills is 

 Glamorganshire cover an old to%vn, the Corporation and mace of which 

 still exist. BlowTi sands have consolidated and form building -stone in 

 Cornwall and north Devon. Some consolidation has taken place in western 

 and northern Irish sand-hills ; good examples occur at Portsalon, Pollan 

 Bay, and on the Sligo coast. 



The lecture was illustrated bv over 80 lantern slides, taken mainlv bv 

 the lecturer ; by a number of dune -building plants sent by Mr. Manning, 

 of Rosapenna, to show the long creeping roots, and a large series of land 

 shells which live on sandy areas, exhibited by Arthur W. Stelfox. At its 

 conclusion Dr. Dwerryhouse, F.G.S., addressed the meeting, and, after the 

 President's reply, the election of a new junior member terminated the 

 proceedings. 



November 29. — Geological Section. — Lecture by Dr. A. R. Dwerry- 

 house, F.G.S., on " Water supply from underground sources," illustrated 

 with lantern slides. W. J. C. Tomlinson, Chairman of the Section, 

 presided. Dr. Dwerryhouse called attention first to the fact that water 

 supply from underground sources was equally dependent upon the rain- 

 fall, with that obtained from surface streams, though it often happened 

 that the fall of level of underground water did not take place for some 

 considerable time after the drought to which it was due had ceased. Thus 

 in estimating the possible supply from wells, it was necessary not only to 

 consider the area over which the rock yielding the water occurred at the 

 surface, but also the amount of rainfall available. This involved a know- 

 ledge of the mean annual rainfall of the district, the amount of run-off 

 by brooks and rivers and the amount of evaporation, including vegetable 

 transpiration, since the amount of percolation is the annual rainfall, less 

 the run -off and evaporation. The relative amount of water passing away 

 by streams, evaporation, and percolation varied much in different localities, 

 being dependent upon climate, the slope of the ground and the nature of 

 the rocks. As the result of experience it was usual for purposes of water 

 supply to make a deduction from the mean annual rainfall of one -fifth or 



