e the keystone of a bridge
into the ringstones of the arch when the work is in the act of being
completed,--during some of those terrible convulsions which cracked and
rent the earth's crust, as if it had been an earthen pipkin brought to a
red heat and then plunged into cold water. Its consequent occurrence in
a lower tier of the geological edifice than that to which it originally
belonged has saved it from the great denudation which has swept from the
surface of the surrounding country the tier composed of its contemporary
beds and strata, and laid bare the grauwacke on which this upper tier
rested. But where it presents its narrow end to the sea, as the older
houses in our more ancient Scottish villages present their gables to the
street, the waves of the German Ocean, by incessantly charging against
it, propelled by the tempests of the stormy north, have hollowed it
into the Bay of Gamrie, and left the more solid grauwacke standing out
in bold promontories on either side, as the headlands of Gamrie and
Troup.

In passing downwards on the fishing village of Gardenstone, mainly in
the hope of procuring a guide to the ichthyolite beds, I saw a laborer
at work with a pickaxe, in a little craggy ravine, about a hundred yards
to the left of the path, and two gentlemen standing beside him. I paused
for a moment, to ascertain whether the latter were not brother-workers
in the geologic field. "Hilloa!--here,"--shouted out the stouter of the
two gentlemen, as if, by some _clairvoyant_ faculty, he had dived into
my secret thought; "come here." I went down into the ravine, and found
the laborer engaged in disinterring ichthyolitic nodules out of a bed of
gray stratified clay, identical in its composition with that of the
Cromarty fish-beds; and a heap of freshly-broken nodules, speckled with
the organic remains of the Lower Old Red Sandstone,--chiefly occipital
plates and scales,--lay beside him. "Know you aught of these?" said the
stouter gentleman, pointing to the heap. "A little," I replied; "but
your specimens are none of the finest. Here, however, is a dorsal plate
of Coccosteus; and here a scattered group of scales of Osteolepis; and
here the occipital plates of _Cheirolepis Cummingiae_; and here the spine
of the anterior dorsal of _Diplacanthus striatus_." My reading of the
fossils was at once recognized, like the mystic sign of the freemason,
as establishing for me a place among the geologic brotherhood; and the
stout g