IP ART OF MAKING GUK-FLINTS. 



itone is found. It cxifts in the chalky calcareous ftones, raj 

 chalks more or lefs fine arid folid, and in marles. l They form 

 horizontal ftrata, by the manner in which the large and ("mall 

 mafles are placed beiide each other. Neverthelefs, as the 

 blocks of filex do not accurately touch each other, there is no- 

 Solution of continuity between the upper and lower mafies of 

 chalk. 



Out of twenty beds of (ilex lying one above the other, at a 

 diftance of twenty feet o*r lefs, there will frequently be no 

 more than one, and very feldom two, which afford good (tones 

 of this defcription ; but in the bed which affords them, almoft 

 all the blocks have a greafy appearance, and in the other 

 ilrata fcarcely any of this defcription will be found. Accord- 

 ingly the good ftrata are followed by fubterraneous excavation s r 

 frequently at confiderable expence, while the others are neg- 

 letfed. 



On the banks of the Cher the flints are explored in a plain, 

 by digging fhafts to the depth of 40 or 50 ieet, from whence 

 horizontal galleries are carried into the only good ftratum 

 which is known. 



On the banks of the Seine in the hills of La Roche Guion, 

 the cliffs of chalk prefent ft eep precipices, where the ftrata of 

 filex are expofed ; and one of thefe ftrata, which contains 

 good ftones for gun-flints, is about fix toifes from the upper 

 furface of the great «nafs of chalk. 

 Inftruments. 

 The inftruments ufed for faflnoning the gun-flints are four 

 in number : 



1. A lmal! piece of iron or mace, with a fquare head, 

 Plate V. Fig. I . the weight of which does not exceed two 

 pounds, or perhaps a pound and a half, with a handle feven 

 or eight inches long. This iniirument is not made of fteel, 

 becaufe if it were to;> hard, its ftroke might (hatter the -flint, 

 inftead of breaking it by a clear fraclure. 

 The hammer. 2. A hammer with two points, in which the pofition of the 

 points is of confeqnence as to the nature of the ftroke, Fig, 2. 

 This hammer, which muft be of good fteel well hardened, 

 and does not weigh more than (ixteen ounces ; fome do not 

 exctred ten. It is fixed on a handle feven inches long, which 

 paiTes through it in fuch a manner, that the points of the ham- 

 mer are nearer the hand of the workman, than the center of 



gravity*. 



Defcription of 

 tools or inftru- 

 ments. 

 The mace. 



