ALUM SHALE. 159 



the inequalities in its bed, by what it washes away from the shores ; 

 especially on this coast, where the waste is so considerable ; yet 

 inequalities by no means trivial are still found in front of our cliffs. 



The rock that lies before Whitby harbour, known by the name 

 of Whithy rock, affords illustotions of these remarks. This rock, 

 fatal to many a gallant ship, forms a kind of triangle, the base of 

 which extends from Saltwick to the point of Whitby east pier, while 

 the apex lies about N. N. E. of the pier head, at the distance of nearly 

 seven furlongs. The angle formed at the pier head is somewhat 

 obtuse, being a little larger than a right angle. The side extending 

 from thence to the apex coincides with the line of the great break 

 formerly mentioned. It forms a steep edge througliout its whole 

 extent, especially towards the apex ; for while the depth of water on 

 the rock, when the tide is out, is only five, six, or seven feet, even 

 towards the outermost point, the depth immediately on the west side 

 of the rock is three or four fathoms about the middle of the line, and 

 increases, towards the apex, to eight, ten, twelve, or even fourteen 

 fathoms ; nay, at a short distance out from the point of the rock, it 

 reaches nineteen or twenty fathoms. Along the other side of the 

 triangle, from the apex to Saltwick, the water deepens still more 

 rapidly. Hence, the point of Whitby rock forms a submarine pro- 

 montory, having submarine cliffs on the west and on the north-east, 

 nearly equal in height to the cliffs on the west side of Whitby harbour. 



As the sea water appears to preserve the rocks which it covers, 

 and as the western edge of Whitby rock is in a line with the great 

 break at the entrance of the harbour, we may presume, that the limits 

 of that rock mark out nearly the original extent of the cliffs on the 

 east side of the hai'bour, at the period when the present bed of the 

 sea on this coast was formed, by the general sinking of the strata on 

 the outside of the rock, and the partial subsidence of those on the 

 west. Ou tliis supposition, we might calculate the time when the 



