REVIEWS GEOLOGY OF NOTTINGHAMSHIRE, ETC. 115 



ferruginous beds, which gradually pass into a coarse yellow Magnesian 

 Limestone. Professor Sedgwick thus continues : — " This red dolomitio 

 sandstone rises and falls in long sweeping undulations, and may be 

 traced to a quarry on the side of the Chesterfield Road, where it preserves 

 nearly tbe same colours and external characters, and is worked for the 

 same purposes. In the whole range of the Magnesian Limestone I know 

 of no deposit which can be compared with that which is here described ; 

 and it is more remarkable, as it is found in the heart of the formation, 

 and nearly in a line with the finest specimens of crystalline dolomite." 

 Mr. Aveline believes, though he could get no certain proof, that these 

 beds are the same (altered in colour by an excess of iron and slightly 

 varying in structure) as the white sandstone of Mansfield. It is this 

 continual change of character, the various kinds of limestone being found 

 to extend over very limited areas, that constitutes the most remarkable 

 circumstance connected wtih the Magnesian Limestone of this district. 

 Although the ravine called Creswell Crags is described, we miss any 

 reference, except in a foot-note, to the recent remarkable discovery in the 

 caves there, by the Rev. J. M. Mello, of a valuable collection of mammalian 

 and of pre-historic human remains. In other respects the memoir is 

 admirably written, and is of far greater importance than might be 

 inferred from the number of pages it contains. 



J. S. 



On the Manufacture of Gun-flints, the Methods of Excavating for Flint, 

 the Age of Palceolithic Man, and the Connection betiueen Neolithic Art 

 and the Gun-flint Trade. (Geological Survey Memoir.) By Sydney 

 B. J. Skertchly, F.G.S. 80 pp., 71 woodcuts. Price 17s. 6d. 



This is a very valuable and interesting account of an industry which will 

 probably soon become extinct. Gun-flints are now only made (in the 

 British Isles) at Brandon, a small town in Suffolk, on the Little Ouse, 

 about six miles west of Thetford. There are now engaged in the trade 

 thirty-six men and boys. The manufactured flints are chiefly purchased 

 by Birmingham and Sheffield merchants for export to Africa, &c, 

 although for horse pistols and large duck guns they are still used in this 

 country. The exact date of the introduction of flint for fire-arms is 

 unknown, and it seems to have been preceded for this purpose by pyrites, 

 for we find that " in 1586 Julius, Duke of Brunswick, had pyrites 

 collected for his fire-arms, near Seefen, and even worked it into shape 

 himself." Gun-flints were superseded in England by percussion caps 

 about the year 1835, and so complete was the change that flint-locks 

 ceased to be manufactured for home use soon afterwards. By experi- 

 ment Mr. Skertchly found that a flint was used up after about thirty 

 shots. 



The flints used by the Brandon knappers are extracted from the 

 Upper Chalk of Lingheath, about a mile distant from the town. The 

 digging or " getting " of the flint is quite a distinct branch from that of 

 its manufacture. In Grimes's Graves, about three miles north-east of 

 Brandon, it seems probable that we have old pits excavated by Neolithic 



