32 IRON SAND FORMATION, 



" The last stone is fine enough to set a razor. The Sussex limestone 

 upon trial has been found to be superior both to the JVIaidstone and Ply- 

 mouth stone, and it is now acknowledged that no cement equal to it in 

 the kingdom has been discovered. It is the received opinion, that the 

 limestone ranges eight miles from east to west, and one mile from north 

 to south*." 



At Terrible Down, six miles and a half north-east from Lewes, the 

 iron sand lies beneath a thick alluvial deposit of loam, sand, and marl, 

 interspersed with thin laminae of ironstone shale, and rounded fragments 

 of sandstone. These beds extend to Eason's Green -j-, (where they are 

 succeeded by a dark blue clay, containing shelly limestone, which appears 

 immediately beneath the turf, and is of very considerable thickness. 

 Proceeding northwards, the clay forms a gentle declivity, which is skirted 

 at the bottom by a rivulet : on the opposite side of the stream it swells 

 into a low hill, and terminates in a valley near the ninth mile-stone. 



Here the sand and sandstone re-appear at the surface, rising from 

 beneath the clay, and gradually uniting with the higher strata of the 

 Forest ridge, near the Elack-boys, 



From the absence of natural sections, the relative position of the clay 

 and sandstone is involved in some obscurity ; but the former, with its 

 imbedded Hmestone, is so perfectly analogous to that of Ashburnham 

 above described, that there can be no hesitation in considering them as 



* Young's Agricultural Survey. -f- Vide Tab. 3, figs. 2 and 3. 



