THE OLD RED SANDSTONE. 193 
or basin on the one s:de, the range of the Lammermuirs and 
the Pentland group on the other; the space between is ridged 
and furrowed in long lines, that run in nearly the same direc- 
tion from north-east to south-west, as if, when the binding 
frost was first setting in, the wind had blown from off the 
northern or southern shore. 
But whence these abrupt, precipitous hills that stud the 
landscape, and form, in the immediate neighborhood of the 
city, its more striking features? They belong —to return tc 
the illustration of the twice-frozen lake — to the middle peri- 
od of thaw, when the ice broke up; and, as they are com- 
posed chiefly of matter ejected from the abyss, might have 
characterized equally any of the other formations. Their 
very striking forms, however, illustrate happily the operations 
of the great agencies on which, in the secondary and transi- 
tion deposits, all the peculiarities of scenery depend. The 
molten matter from beneath seems to have been injected, in 
the first instance, through rents and fissures among the car- 
boniferous shales and sandstones of the district, where it lay 
cooling in its subterranean matrices, in beds and dikes, like 
metal in the moulds of the founder; and the places which it 
occupied must have been indicated on the surface but by 
curves and swellings of the strata. The denuding power 
then came into operation in the form of tides and currents, 
and ground down the superincumbent rocks. The injected 
masses, now cooled and hardened, were laid bare; and the 
softer framework of the moulds in which they had been cast 
was washed from their summits and sides, except where long 
ridges remained attached to them in the lines of the current, 
as if to indicate the direction in which they had broken its 
force. Every larger stone in a water-course, after the tor- 
rent fed by a thunder shower has just subsided, shows on the 
I9* 
