I do not wish to minimize the value of cross-country traverses carried out with special scientific objects; they are, indeed, often necessary for topographical and geological purposes. I would, however, warn the enthusiastic tyro that, in the Libyan Desert, travelling as the crow flies is not always so simple and glorious an affair as it may seem when planning expeditions from a comfortable arm-chair; and if his object is to get a short cut he will probably have reason to bitterly regret the moment he left the beaten track. I have in mind more than one instance where mistakes of this kind have been made, mistakes which might easily have led to disastrous consequences. In long cross-country traverses an error in steering of only two or three degrees will in a few marches throw a caravan many kilometres out of its course, and guiding camels over rough country by compass is by no means an easy undertaking. Moreover, easily distinguishable landmarks are rare, and the desert plains over wide areas maintain remarkably persistent characteristics. Quite recently I recollect an Englishman, whose Arab attendant had become suddenly incapacitated by an attack of fever or sunstroke, getting hopelessly astray between the edge of the plateau overlooking the oasis and rail-head, which was then only 20 or 30 kilometres distant, in consequence of his missing the bifurcation of the road at El Shugera, and proceeding, owing to this mistake, along the route leading to Sohag. Along the caravan roads the sharp fragments of rock have been stamped underground or kicked to one side, but elsewhere they usually litter the surface, and are very trying to camels, whose pads, though soft and yielding, are easily worn by much travelling over rough country. This has more than once been painfully impressed upon me by the antics of my own riding camel, whose mode of progression at such times resembled more the dance of a fanatic on red-hot coals than the ordinary gait of a well-bred ‘hegîn.’ Over some areas, however, one can travel in a straight line without let or hindrance, and in such cases it is only necessary to lay out the course correctly in the first instance, and to have the courage of one’s opinion to stick to that course until the destination is reached. One must not heed the remonstrances of the less sporting members of the expedition, who will lose no opportunity of predicting disaster, and in this respect the new chum fresh out from home is generally the greatest offender.