196 Dr., Bright on the Strata 



of stratified yellow sandstone, forming what has been called an up- 

 iilling. In the fissures of this rock crystals of carbonate of lime are 

 found, and crystals of sulphate of strontian, which often assume a 

 radiated form. This sandstone, having sometimes the appearance of 

 a breccia extends to Redland. It is probably spread over the surface 

 of the siliceous iron-stone already described ; and in such a position 

 it seems to have been found on Kingsdown in digging the vaults of 

 Portland Chapel. The sandstone was there less firmly agglutinated, 

 and the sulphate of strontian occurred about 4 feet below the surface 

 in large irregular balls weighing many pounds.* At Redland this 

 sandstone and the strata upon which it rests are rather abruptly ter- 

 minated, being covered by a limestone stratified horizontally in thin 

 layers, containing ammonites, gryphites, and anomise in abundance, 

 and agreeing in all its characters with the well known limestone 

 called lyas. The lyas extends to Cotham, where some of the strata 

 are remarkable for taking a beautiful polish, being known at Bristol 

 by the name of the Cotham stone. This lyas burns to a brown 

 lime which sets hard under water. 



But to return to the limestone. I do not intend to describe in 

 detail all the beds of it ; but the following are what I thought best 

 deserving of notice, from their commencement immediately below 

 the coal down to the lowest in the series. The first part of the 

 series is best observed on the northern bank of the river. 



* A beautifully crystallized specimen from these excavations was presented to tlic 

 Society by Mr. Cumberland. It was found together with many other masses of the same 

 substance imbedded in yellow marl. On digging the excavation for some houses at Clifton, 

 according to Mr. Cumberland, the following minerals were found, but it is not known in 

 what bed the vein occurred to which they belonged. Crystals of galena with foliated 

 sulphate of strontian upon a matrix of sulphate of barytes. Quartz crystals enveloping 

 ueedles of sulphate of strontian. These excavations are now closed, and the ground being 

 built upon the minerals can no longer be procured. 



