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1653 E. Manlove Liberties & Customes Lead-mines Derby 264 Primgaps, Roof-works, Flat-works, Pipe-works, Shifts.

1684 Fawside Coal Compt 125 For ruffe coall takeing doune, £5.

1754 Zimmerman in T. G. Smollett tr. Select Ess. Commerce, Agric., Mines, Fisheries 263 It lies above the pitch-coal, and is by the miners called roof-coal.

1839 A. Ure Dict. Arts 978 The roof-stratum begins to break by the sides of the pillars.

1845 J. Phillips & C. G. B. Daubeny Geol. in Encycl. Metrop. VI. 704/1 An idea of the appearances of the Hutton roof crags.

1887 P. McNeill Blawearie 134 The day on which I got my head crushed wi' the fa' o' roof-coal.

1935 Amer. Mineralogist 20 598 The narsarsukite was seen only in the quartz veins in the roof rock and upper part of the intrusive.

1954 Sewage & Industr. Wastes 26 655/1 The most highly acid-forming seams studied have a high sulfur content in the roof strata.

2001 E. V. Stanis & B. I. Maskovtsev in R. N. Yong & H. R. Thomas Geoenvironmental Engin. 89 This was caused by a caving of the roof rocks in the air heading, from which the support had been removed.