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 imputed the false relations of travellers, where there is no imaginable motive to deceive.  They trusted to memory, what cannot be trusted safely but to the eye, and told by guess what a few hours before they had known with certainty.  Thus it was that Wheeler and Spon described with irreconcilable contrariety things which they surveyed together, and which both undoubtedly designed to show as they saw them.

When we had satisfied our curiosity in the cave, so far as our penury of light permitted us, we clambered again to our boat, and proceeded along the coast of Mull to a headland, called Atun, remarkable for the columnar form of the rocks, which rise in a series of pilasters, with a degree of regularity, which Sir Allan thinks not less worthy of curiosity than the shore of Staffa.

Not long after we came to another range of black rocks, which had the appearance of broken pilasters, set one behind another to a great depth.  This place was chosen by Sir Allan for our dinner.  We were easily accommodated with seats, for the stones were of all heights, and refreshed ourselves and our boatmen, who could have no other rest till we were at Icolmkill.