This book is in no sense a diary of day-to-day travel. Only a single chapter is devoted to the account of the extraordinary journey which Captain Buchanan and his cinematographer, Mr. Glover, made from Kano in Nigeria to Touggourt in Algiers—a journey of over 3,500 miles through the great desert of Africa. Some idea of the hardships which they encountered may be gathered from the fact that, while they started with a caravan of thirty-six camels and fifteen natives, they finished with a single camel and only two natives, after fifteen months of travel. The reader is never wearied by monotonous logs of distances covered day by day or of the countless difficulties overcome on the long long trail. Only the last few days, when victory was in sight, are briefly sketched. But in earlier chapters we have vivid pictures of the perils that are inseparable from travel over vast sandy wastes, where a burning sun beats down with relentless fury, and where the lives of men and beasts alike depend on their finding water at least every six or seven days. One chapter describes one of the sandstorms that all but engulfed the caravan in the shelterless plain—another, the rare experience of torrential rain which may be almost as devastating, but, unlike the sandstorm, is fraught with blessing, for it brings food to the starving mammals that haunt the fringe of the great desert. The author’s knowledge of the Sahara is not based merely on the one long journey which took him across its widest part. The book is partly based on a previous lengthy visit to the Sahara, during which he studied the fauna of the district as it has never been studied before, and the weird and impoverished races which are found in its habitable areas. The Sahara is not a mere plain of sand—it embraces more than one mountainous and picturesque area as large as Wales, but, unlike that country, arid in the extreme; besides numerous oases where a scanty subsistence is yielded by palms for small communities, and which are largely dependent on the visits of travelling caravans in quest of that most precious of all commodities—water. In these places, isolated by vast seas of desert, dwell the remnants of tribes once more numerous, who migrated thither when conditions were more favourable, for alas! Captain Buchanan’s observations lead him to the conclusion that the constantly accumulating sand-drifts are gradually destroying the already scanty resources of the still inhabited portions. Readers will find interest in his description of the two oases of Bilma and Fachi, both of which derive their subsistence from salt-mines, and whose dwellings and the forts which protect them are built entirely of blocks of salt, now blackened by age.