It should be understood that I do not profess to give exhaustive treatises on each of the numerous subjects comprised in this volume, but only such information as is not generally known among travellers.  A striking instance of the limited geographical area over which the knowledge of many useful contrivances extends, is that described as a ‘Dateram,’ p. 164, by which tent ropes may be secured in sand of the loosest description.  Though tents are used over an enormous extent of sandy country, in all of which this simple contrivance would be of the utmost value on every stormy night, and though the art of pitching tents is studied by the troops of all civilised and partly civilised nations, yet I believe that the use of the dateram never extended beyond the limits of a comparatively small district in the south of the Sahara, until I had described it in a former Edition; and further, my knowledge of that contrivance was wholly due to a single traveller, the late Dr. Barth.

The first Edition of the ‘Art of Travel’ was published in 1854:  it was far less comprehensive than the later ones; for my materials steadily accumulate, and each successive Edition has shown a marked improvement on its predecessor.  Hitherto I have adhered to the original arrangement of the work, but am now obliged to deviate from it, for the contents have outgrown the system of classification I first adopted.  Before I could interpolate the new matter prepared for this Edition, I found it necessary to recast the last one, by cutting it into pieces, sorting it into fresh paragraphs and thoroughly revising the writing—­disentangling here and consolidating there.  The present Edition will consequently be found more conveniently arranged than those that preceded it, and, at the same time, I trust the copiousness of its Index will enable persons to find with readiness any passage they had remarked in a former Edition, and to which they may desire again to refer.

I am still most thankful to strangers as well as to friends for contributions of hints or corrections, having been indebted to many a previously unknown correspondent for valuable information.  I beg that such communications may be addressed to me, care of my publisher, Mr. Murray, 50, Albermarle Street, London.

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P.S.—­A reviewer of my Third Edition accused me of copying largely from an American book, called ‘The Prairie Traveller,’ by, the then, Capt.  Randolph B. Marcy.  I therefore think it well to remark that the first Edition of that work was published in 1859 (Harper and Brothers, New York;—­by authority of the American War Department), and that the passages in question are all taken from my second Edition published in 1856; part of them are copies of what I had myself written, the rest are reprints of my quotations, as though the Author of the ’Prairie Traveller’ had himself originally selected them.