32 Notices of Memoirs — W. Whi taker — Brighton Waterworks. 



upper part of the parish . of Halkirk is covered by drift-gravel, 

 underlying peat. At Loch More flagstones are presented. Below 

 the lake may be traced the banks of what was once a great river. 

 At Dirlot the rocks are sandstone, granite, gneiss, gneissic con- 

 glomerate, and limestone. At Dalmore the right bank of the Thurso 

 is composed of Boulder-clay, the left of gravel. Here is seen a 

 chain of moraines, composed of granitic gravel and sand. At 

 Tormsdale a vein of some cinder-like material occurs. The flag- 

 stones at Poll a' Chreagan are covered with freestone, as also at 

 Dale Bridge on the right bank of the river. On the left the flags 

 lie exposed in great tabular masses, overlying limestone. At the 

 top of the Mill Pool are the remains of a natural dam. Below this 

 pool a band of freestone once crossed the bed of the river. At Dale 

 are shifting beds of gravel, and here the river is continually changing 

 it course. Below Polihour flags again appear, and opposite Scots 

 Calder are banks of Boulder-clay, the boulders therein being very 

 distinctly striated. Great masses of flagstone block up the bed of 

 the stream at Gerston. At Halkirk the cliffs are coated with red ochi'e. 



Granite is not visible at Dorrery, as has been stated by at least one 

 writer, but it does not appear to lie at any great depth below the flags. 



At Achanarras a curious fossil fish, Coccosteus, is found in a small 

 slate quarrjr. 



East from Spittal the angle at which the rocks dip gradually 

 diminishes, and at Lanergill reaches its nearest approach to a dead 

 level. 



Drift gravel prevails in the neighbourhood of Halsary, and also 

 down part of Strathberg, where the banks of the ancient river may 

 again be traced. Here the Dalmore moraines are continued. 



No evidence of volcanic action can be gathered from an examina- 

 tion of the rocks of Central Caithness, but the district presents a 

 fair field for the study of erosion by ice, air, and water. 



V. — On the Waterworks at Goldstone Eoad, Brighton. 

 By W. Whitaker, B.A., F.G.S., Assoc Inst.C.E. 



NOTES of a visit underground in December 1884, when the water 

 was pumped down for extending the galleries. These works 

 are perhaps the best example of the right way of getting a very 

 large supply of water from the Chalk, galleries being driven (in one 

 case to the length of 800 feet) at about low-water level, so as to 

 cut the fissures and intercept the water on its way to the sea. 



The whole of the works (shafts and galleries) are in the White 

 Chalk, with but few flints in the bedding-planes, but with many 

 oblique layers along joint-planes. The supply comes chiefly from a 

 few powerful springs, and, though small contributions issue between 

 these, it is noteworthy how far a tunnel has sometimes been driven 

 before reaching a fissure of large yield. Under these circumstances 

 borings, or even shafts, might have failed to yield a large supply. 



The roof of the north-eastern gallery is throughout of one bed, 

 rarely needing support, a thin brittle layer of flint at its base being 

 cleared away. 



