58 
DESCRIPTION OF THE COAST. 
careous masses. At Hackness alone it is worked as a building stone : it 
is there very soft in the quarry, and may be chiselled and wrought with 
the utmost facility. It has at the same time, the property of hardening 
by exposure ; and, possessing both beauty and durability, is a very 
valuable building stone. Its durability is evinced by the condition 
of the stone in the ancient church at Hackness, which was probably 
built about the end of the thirteenth century, and its good effect in 
architecture may be seen to great advantage in the new Church and new 
Museum at Scarborough, and especially in the Museum of the Yorkshire 
Philosophical Society, in the construction of which blocks of great mag- 
nitude have been employed. 
Its thickness is generally above thirty feet : the upper bed is usually 
very thick, hard, and irony, full of gryphasas, belenmites, &c., so as 
to be unfit for building. In the quarry at Hackness, the ammonites 
Calloviensis, Koenigi, subleevis, &c. which so eminently characterise the 
stratum, lie on the top of the rock just below the Oxford clay. At 
Scarborough, they lie a little deeper in the stone. On account of its 
comparative hardness, the upper beds of this rock project on the hill 
sides beyond the slopes of the incumbent clay, and form little buttresses 
beneath those remarkable “ nabs” by which the calcareous grit is recog- 
nised in the vicinity of Scarborough. 
That stratum of the oolitic series, which, in the south of England, 
Mr. Smith named the “ cornbrash,” is well known to be a very variable 
rock as to its substance and thickness, but remarkably well characterised 
by its fossils. It is by their aid that we have traced this thin and other- 
wise unimportant rock, with hardly a single interruption, from Dorset- 
shire to Lincolnshire. It is, therefore, by organic fossils and geological 
position alone, that we can expect to recognise the cornbrash on the coast 
of Yorkshire. By these characters, it may be satisfactorily identified : 
it usually appears as a single, thick, fissile, calcareous bed, lying almost 
in contact with the bottom of the Kelloways rock ; but eminently dis- 
tinguished from it by the nature of its substance, and the shells with 
which it is filled. Without close attention, so thin a layer can hardly 
