earlier part of the day was to be
in all probability the better part of it, and that the harvest of
observation which it was ultimately to yield might be found to depend on
the prompt use made of the passing hour. What first attracts the
attention of the geologist, in journeying westwards, is the altered
color of the boulder-clay, as exhibited in ditches by the way-side, or
along the shore. It no longer presents that characteristic red
tint,--borrowed from the red sandstone beneath,--so prevalent over the
Black Isle, and in Easter Ross generally; but is of a cold leaden hue,
not unlike that which it wears above the Coal Measures of the south, or
over the flagstones of Caithness. The altered color here is evidently a
consequence of the large development, in Ferindonald and Strathpeffer,
of the ichthyolitic members of the Old Red, existing chiefly as fetid
bituminous breccias and dark-colored sandstones: the boulder-clay of
the locality forms the dressings, not of red, but of blackish-gray
rocks; and, as almost everywhere else in Scotland, its trail lies to the
east of the strata, from which it was detached in the character of an
impalpable mud by the age-protracted grindings of the denuding agent. It
abounds in masses of bituminous breccia, some of which, of great size,
seem to have been drifted direct from the valley of Strathpeffer, and
are identical in structure and composition with the rock in which the
mineral springs of the Strath have their rise, and to which they owe
their peculiar qualities.

After walking on for about eight miles, through noble woods and a lovely
country, I struck from off the high road at the pretty little village of
Evanton, and pursued the course of the river Auldgrande, first through
intermingled fields and patches of copsewood, and then through a thick
fir wood, to where the bed of the stream contracts from a
boulder-strewed bottom of ample breadth, to a gloomy fissure, so deep
and dark, that in many places the water cannot be seen, and so narrow,
that the trees which shoot out from the opposite sides interlace their
branches atop. Large banks of the gray boulder-clay, laid open by the
river, and charged with fragments of dingy sandstone and dark-colored
breccia, testify, along the lower reaches of the stream, to the near
neighborhood of the ichthyolitic member of the Old Red; but where the
banks contract, we find only its lowest member, the Great Conglomerate.
This last is by far the mos