ure's riddles these seemed to me to be at once the most
interesting and the most difficult to expound. I treasured them
carefully up, and was told by one of the workmen to whom I showed them
that there was a part of the shore, about two miles further to the west,
where curiously shaped stones, somewhat like the heads of
boarding-pikes, were occasionally picked up, and that in his father's
day the country people called them thunderbolts. Our first half-holiday
I employed in visiting the place where the thunderbolts had fallen so
thickly, and found it a richer scene of wonder than I could have
fancied even in my dreams.

My first year of labour came to a close, and I found that the amount of
my happiness had not been less than in the last of my boyhood. My
knowledge had increased in more than the ratio of former seasons; and as
I had acquired the skill of at least the common mechanic, I had fitted
myself for independence.

My curiosity, once fully awakened, remained awake, and my opportunities
of gratifying it have been tolerably ample. I have been an explorer of
caves and ravines, a loiterer along sea-shores, a climber among rocks, a
labourer in quarries. My profession was a wandering one. I remember
passing direct, on one occasion, from the wild western coast of
Ross-shire, where the Old Red Sandstone leans at a high angle against
the prevailing quartz of the district, to where, on the southern skirts
of Midlothian, the Mountain Limestone rises amid the coal. I have
resided one season on a raised beach of the Moray Firth. I have spent
the season immediately following amid the ancient granite and contorted
schists of the central Highlands. In the north I have laid open by
thousands the shells and lignites of the oolite; in the south I have
disinterred from their matrices of stone or of shale the huge reds and
tree ferns of the carboniferous period.

I advise the stone-mason to acquaint himself with geology. Much of his
time must be spent amid the rocks and quarries of widely separated
localities, and so, in the course of a few years he may pass over the
whole geological scale, and this, too, with opportunities of observation
at every stage which can be shared with him by only the gentleman of
fortune who devotes his whole time to study. Nay, in some respects, his
advantages are superior to those of the amateur, for the man whose
employments have to be carried on in the same formation for months,
perhaps years, enjoys