rock-headn.

1660 R. Stapleton tr. Juvenal Mores Hominum 183 They are headlong tost Like stones from Precipices, when th' earth slides And leaves to the rock-head no mountain-sides.

1785 G. Forster tr. A. Sparrman Voy. Cape Good Hope I. vi. 258 At the water-side it [sc. the shore] is low, one place excepted, which, at a very small distance from the water, appears with a rock-head, as it is called, or a rocky hill, flat on the top, which at the sea-side is perpendicular.

1793 J. Sinclair Statist. Acct. Scotl. VI. 419 There are two public roads... One leads straight from Tarbat-Ness to the ferry of Cromarty, and is called the rock-head road, from its being carried along the top of a bank..rocky in some parts.

1853 Q. Jrnl. Geol. Soc. 9 209 Sea-birds nestle over the whole surface of the island, under every little rock-head that can afford shelter.

1895 Antiquary 31 251/2 The lustration-basin would indicate rites having reference to the rock-head close by.

1985–6 Lifeboat Winter 256/2 The lifeboat approached bow first..and, avoiding the many rockheads in the area, manoeuvred to within 15ft of the yacht's 8ft bowsprit.

1808 H. Holland Gen. View Agric. Cheshire i. 40 Most of the pits in the neighbourhood of Northwich and Winsford have such a communication at the rock-head, as is made apparent by the brine in one pit having its level lowered, when another pit is at work, at some distance.

1883 Times 13 Aug. 11/6 Brine again stands over the rock head, and is very plentiful.

1916 Brit. Ruling Cases Courts of Great Brit. V. 243 Prior to 1835 salt was obtained..by sinking a shaft down to the top of the upper bed, and..pumping up what was called ‘rockhead brine’, or, in other words, water impregnated with dissolved rock salt.

2006 A. Fielding & A. Fielding Salt Industry 44 As one moves further away from the extraction point so more fresh water is pulled over the rock salt and the rock head dissolves more quickly.

1820 Edinb. Encycl. (1830) XIV. 345/1 The instant the pit is sunk to the rock head, a bore is put down to the mine.

1875 J. Croll Climate & Time xxix. 467 It is seldom that the geologist has an opportunity of seeing a complete section down to the rock-head in such a place.

1905 G. L. Kerr Pract. Coal Mining (rev. ed.) iii. 43 The surface soil is excavated,..until a convenient depth or the rock head is reached.

1978 G. L. Herries Davies & N. Stephens Ireland iv. 98 Borings at the head of Lough Foyle have shown the rock-head to lie some 30 m below Ordnance datum.

1994 Jrnl. Coastal Res. 10 339 The main purpose was to investigate the unconsolidated sediment infill, but incidental information on the first few meters of the underlying rockhead has been obtained.

1835 J. Holland Hist. & Descr. Fossil Fuel, Collieries, & Coal Trade 175 The great thickness of alluvial cover..completely hides the crop or outburst of the strata, termed generally by miners the rock-head, from our view.

1839 A. Ure Dict. Arts 960 The outcrop or basset edge of the strata, called by miners the rock-head.