THE OLD RED SANDSTONE. 199 
has been the process through which coast-lines that were 
originally paved slopes have become walls of precipices. 
The waves cut first through the outer strata; and every 
stratum thus divided comes to 28th faces — a perpen- 
dicular face in the newly-formed line of precipice, and another 
horizontal face lying parallel to it, along the shore. One 
half the severed stratum seems as if rising out of the 
sea, the other half as if descending from the hill: the 
geologist who walks along the beach finds the various beds 
presented in duplicate —a hill-bed on the one side, and a 
sea-bed on the other. There occurs a very interesting 
instance of this arrangement in the bold line of coast on the 
northern shore of the Moray Frith, so often alluded to ina 
previous chapter, as extending between the Southern Sutor 
and the Hill of Eathie; and which forms the wall of a por- 
tion of the roof-like ridge last described. The sea first broke 
in a long line through strata of red and gray shale, next 
through a thick bed of pale-yellow stone, then through a con- 
tinuous bed of stratified clays and nodular limestone, and, 
last of all, through a bed, thicker than any of the others, of 
indurated red sandstone. The line of cliffs formed in this 
way rises abruptly for about a hundred yards on the one 
hand ; the shore stretches out for more than double the same 
space on the other; on both sides the beds exactly correspond ; 
and to ascend in the line of the strata from the foot of tne 
cliffs, we have either to climb the hill, or to pass downwaras at 
low ebb to the edge of the sea. The section is of interest, 
not onl- from the numerous organisms, animal and vegetable, 
which its ichthyolite beds contain, but from the illustration 
which it also furnishes of denudation to a vast extent from 
causes still in active operation. A line of precipices a hun- 
dred yards in height, and more than two miles in length, has 
