30 
SPURN POINT. 
that all geological works should be coloured upon one model ; but what 
model shall we follow ? No geological map can possibly be so filled with 
colours as to embrace all the minor subdivisions of rocks, which in local 
sections it would be unpardonable to omit. Besides, the colours of rocks 
vary, and circumstances may make it desirable that sometimes a stratum 
should be coloured strongly to mark its importance, though at other 
times it would be better represented by a fainter shade. However, to 
increase as little as possible the confusion of colours which already exists, 
I have followed in the colours of the oolitic rocks the works of Mr. 
Smith, and have preferred, with Mr. Greenough, to leave the chalk white. 
Where rocks were to be thus represented for the first time, I have used 
such colours as have not been before appropriated. 
The heights of the cliffs are represented above the level of high water 
at spring tide, because this is, upon the whole, the most convenient line 
that can be referred to ; and though it is too variable to serve for the 
rigorous determination of altitude by graduated instruments, it will be 
found accurate enough for geological purposes. The tides rise on this 
coast about fifteen or eighteen feet, and as they very generally lay up 
much sand at the foot of the cliffs, and as at this level we commonly find 
much debris accumulated, it seemed, upon the whole, better, except in 
a few instances, to confine the colouring to the level of high water. It 
remains to state that the following description is in every particular 
original ; and was mostly executed on the spot. 
SPURN POINT. 
The southernmost part of the coast of Yorkshire, is a low peninsula 
of gravel and sand, accumulated by the sea and the wind, and laid in its 
peculiar forms by the united action of currents from the sea and the 
Humber. The materials which fall from the wasting cliffs between 
Bridlington and Kilnsea, are sorted by the tide according to their weight 
and magnitude ; the pebbles are strewed upon the shore, beneath the 
precipice from which they fell ; the sand is driven along and accumu- 
