THE KIMMEBIDGE COAL MOKIY. 86 



at Dorchester, of especial interest from the circumstance of 

 their having attached to them the portion of a ring, or armlet, 

 (pi. vii.) which appears to have been fractured whilst in the 

 lathe, and therefore cast aside by the workman, as refuse. 



Var: 2. The next is that in which the work has been turned 

 upon a square arbor, the hole passing completely through the 

 piece, (pi. vi. fig. 1.) Their smallest diameter is frequently 

 only one inch. 



Var: 8, are with three holes, having been turned upon a 

 three-pronged chuck. Their smallest diameter is a little more 

 than an inch and a half. They are generally much thinner than 

 the preceeding, some being only three eighths of an inch in thick- 

 ness. The holes are placed at the angles of an equilateral triangle, 

 which is faintly traced upon the shale. It is curious to remark 

 in some specimens, traces of the piece having flown out of the 

 lathe before it was finished, owing to the imskilfulness of the 

 workman, (pi. viii. fig. 4.) 



Var: 4, are with two holes, having been turned upon a two- 

 pronged chuck, (pi. ix. fig. 3.) These are less common than 

 any of the preceeding: their diameter is from two inches and a 

 quarter, to less than one inch and three quarters, by half an inch 

 in thickness. 



Var: 5, with four holes, having been turned upon a four- 

 pronged chuck, are very scarce, (pi. ix. fig. 2.) The specimen 

 from which the figure was taken, measured an inch and three 

 quarters in di.imeter, by three eighths of an inch in thickness. 



Var: 6, are, more or less, of a conical shape, (pL viii, & x.) 

 owing to two or more rings having been turned from the same 

 piece. Various chucks have been used for turning them, as the 

 square head, and three-pronged: they vary in height, from two 

 inches and a quarter, to one inch. 



There are besides, three specimens which cannot be classed 

 with either of the foregoing varieties. One of these, measures in 

 diameter three inches and a half, and one inch and a quarter in 

 thickness. It was turned upon a square headed chuck, and the 

 front centre of the lathe appears to have worn away the shale, 

 until it met the chuck, causing a circular hole at ^e bottom of 



