THE BASALT OF ROWLEY REGIS. 
127 
regards the columns, but also as regards each individual 
mass. The columns are sometimes but a few inches in 
diameter, sometimes as much as five or six feet; and it is 
noticeable that the columns do not uniformly consist of 
masses of equal diameter. We should find, taking any 
column at random, that there were, perhaps, three or four or 
even a greater number of similar sized masses; then would 
come a division of the mass into two or more nuclei, and 
again a further subdivision into a very large number of nuclei 
within the original diameter of the column, and again we 
should come to single masses occupying the whole width of the 
column. 
These varying masses of roclie are not continuous over 
the extent of any quarry now open, hut occasionally—between 
—occur masses of the basalt itself, leading on to the solid stone 
below. A face of the quarry showing these columnar masses 
of nodular roclie is a beautiful and interesting sight to the 
geologist, though eminently unsatisfactory to the quarry 
owner. Sometimes the concentric layers weather off in 
places, so that many thicknesses of the covering of the 
nucleus are exposed, and the effect of light and shadow 
resulting therefrom is often striking as well as beautiful. 
The whole of this mass of roclie must be removed before 
the quarry can he worked satisfactorily. 
It has been held, I believe, that this mass of roclie was 
once solid basalt, thrown up from below, and of similar quality 
and hardness to the true stone upon which it rests, and that 
its present state is the result of decomposition due to atmo¬ 
spheric or other influences; but I can see nothing to bear out 
this theory. On the contrary, I believe there is abundant 
evidence to show that we find the roclie exactly as it was to 
be found when it cooled after its eruption, consisting of exactly 
the same component parts as when erupted, and that the rude 
columnar structure in the roclie, as the more perfect columnar 
structure in the true basalt, is due to the cooling of the 
different masses. 
When we see a mass of true basalt occurring here and there, 
side by side with masses of roclie ; when we consider iliat each 
has been subjected to the same influences, that what has 
touched or affected one mass has equally touched and affected 
all; and when we consider the diverseness of the materials as 
they stand now, we cannot come to any other conclusion than 
that both masses are practically now the same as when thrown 
out from Nature’s laboratory. We might, if further proof were 
necessary, find it all over the hills themselves ; proof that the 
true basalt does not weather —remains unchanged under all 
