TH£ UiafERIDOE COAL MONEY. 83 



The material of which they are formed, is a bituminonfl shale 

 called Kimmeridge Coal, of which there are extensive beds on 

 that immediate part of the coast. It is still used by the inhab- 

 itants of the neighbourhood as fuel. It bums freely, with a white 

 ash and slaty residue, and emits a disagreeable bitiuninous odour. 

 A few years since, it was extensively worked for the purpose of 

 making naptha. 



In the first place however, I propose discribing these relics, 

 in their different varieties. In form they are circular, with 

 bevelled and moulded edges, measuring in diameter from three 

 inches and a half to one inch, and in thickness, from nearly one 

 inch to three eighths of an inch. These measurements apply to 

 the flat varieties only. It is evident, from the accuracy with which 

 the circle is universally preserved, and from the regularity and 

 sharpness of the mouldings, that they were turned in a lathe. * 

 They have on one side, two or three, and occasionally, four round 

 holes, or one square hole, for the purpose of fixing them to the 

 chuck, and on the other side a small hole made by the front 

 centre of the lathe. In some instances they are perforated with 

 a single square hole, showing that the piece may be fixed on 

 a square arbor. In most specimens the greatest circumference is 

 found nearest the side by which it was attached to the chuck, so 

 that the bevil on the outside is longer than that on the inside ; 

 in some few however, the greatest circumference is in the centre 

 of the thickness of the piece, and the bevels equal. I have never 

 yet met with a specimen in which the largest bevel, and conse- 

 quently the greatest work, was on the side next the chuck. 



Fragments of the shale are frequently found under the same 

 circumstances as the " Coal Money," which show the marks of 

 cutting tools, as if prepared for the lathe. At Encombe I have 

 found such pieces measuring from four to five inches in diameter, 

 by an inch in thickness. Upon a piece which Mr. Miles obtained 

 from the cliff at Worbarrow, were "traced with mathematical 



I Small narrow chippings of flints are frequently found associated 

 with the *'Coal Money," theb thin sharp edges or points being chipped 

 and broken. It has been suggested that they were used in turning the 

 "Coal Money;" and this has been further confirmed by experiments 

 which prove that the most highly tempered steel does not retain its edge 

 when opposed to the rapidity of the coal when in the lathe. I have a 

 specimen of the "Coal Money," into a fracture of which I found stickini^ 

 a sharply pointed chipping of flint. 



