t thirty feet.

This part of our curiosity was nearly frustrated; for though we went to
see a cave, and knew that caves are dark, we forgot to carry tapers, and
did not discover our omission till we were wakened by our wants. Sir
Allan then sent one of the boatmen into the country, who soon returned
with one little candle. We were thus enabled to go forward, but could
not venture far. Having passed inward from the sea to a great depth, we
found on the right hand a narrow passage, perhaps not more than six feet
wide, obstructed by great stones, over which we climbed and came into a
second cave, in breadth twenty-five feet. The air in this apartment was
very warm, but not oppressive, nor loaded with vapours. Our light showed
no tokens of a feculent or corrupted atmosphere. Here was a square
stone, called, as we are told, Fingal's Table.

If we had been provided with torches, we should have proceeded in our
search, though we had already gone as far as any former adventurer,
except some who are reported never to have returned; and, measuring our
way back, we found it more than a hundred and sixty yards, the eleventh
part of a mile.

Our measures were not critically exact, having been made with a walking
pole, such as it is convenient to carry in these rocky countries, of
which I guessed the length by standing against it. In this there could
be no great errour, nor do I much doubt but the Highlander, whom we
employed, reported the number right. More nicety however is better, and
no man should travel unprovided with instruments for taking heights and
distances.

There is yet another cause of errour not always easily surmounted, though
more dangerous to the veracity of itinerary narratives, than imperfect
mensuration. An observer deeply impressed by any remarkable spectacle,
does not suppose, that the traces will soon vanish from his mind, and
having commonly no great convenience for writing, defers the description
to a time of more leisure, and better accommodation.

He who has not made the experiment, or who is not accustomed to require
rigorous accuracy from himself, will scarcely believe how much a few
hours take from certainty of knowledge, and distinctness of imagery; how
the succession of objects will be broken, how separate parts will be
confused, and how many particular features and discriminations will be
compressed and conglobated into one gross and general idea.

To this dilatory notation must be imp