248 pRorEssoR Hailstone on the " 



radiated pyrites, globular or kidney-form. It is considerably 

 harder than the common chalk and its colour is usually some shade 

 of grey. It is well known in this county under the name of clunch, 

 and is the material from which the best lime is burnt. Some of 

 the beds are hard enough to serve the purpose of building stone, 

 and are quarried and shaped in blocks for that purpose. It also 

 endures the fire well, and, like the Ryegate stone in London, is 

 much esteemed for the backs of grates and other similar appli- 

 cations. 



This stone is dug in the greatest quantities at Reach, a small 

 hamlet in the parish of Burweli, situated on the skirts of the fen 

 country precisely where the Devil's ditch terminates in that di- 

 rection. The excavations at this place are immense. 



Clunch, when burnt, affords a lime in such universal esteem 

 that the crude material is sent from hence for that purpose as far as 

 Peterborough and other distant places, within reach of the water 

 carriage of that level district. 



The bedding of a chalk hill is difficult to ascertain, on account 

 of the great number and irregularity of the rifts and joints inter- 

 .secting the stone in all directions. By careful observations however, 

 made in different places, I am enabled to state that the general 

 direction of the beds is from the N. Ii. to the S. W. and that they 

 have a gentle inclination to the S. E. Their direction consequently 

 coincides with the line that I have mentioned above, as dividing 

 the upper from the lower chalk. 



In one of the pits at Reach a bed of clunch occurs, which differs 

 from the ordinary sort and presents some remarkable appearances ; 

 the mass itself is much harder, and stuck full of concretions of a 

 yellow indurated marl : outwardly they are of a green colour 

 arising from the oxide of iron : they are in general kidney-shaped 



