But it may fairly be claimed for the balloon, even as it now is, that a great and important future is open to it as a means for exploring inaccessible country. It may, indeed, be urged that Andree's task was, in the very nature of the case, well nigh impracticable, and his unfortunate miscarriage will be used as argument against such a method of exploration. But it must always be remembered that in Andree's case the rigours of climate which he was compelled to face were the most serious of all obstacles to balloon travel. The extreme cold would not only cause constant shrinkage of the gas, but would entail the deposition of a weight of moisture, if not of snow, upon the surface of the balloon, which must greatly shorten its life.

It would be entirely otherwise if the country it were sought to explore were in lower latitudes, in Australia, or within the vast unknown belt of earth lying nearer the equator. The writer's scheme for exploring the wholly unknown regions of Arabia is already before the public. The fact, thought to be established by the most experienced aeronauts of old times, and already referred to in these pages, that at some height a strong west wind is to be found blowing with great constancy all round the globe, is in accordance with the view entertained by modern meteorologists. Such a wind, too, may be expected to be a fairly fast wind, the calculation being that, as a general rule, the velocity of currents increases from the ground at the rate of about three miles per hour for each thousand feet of height; thus the chance of a balloon drifting speedily across the breadth of Arabia is a strong one, and, regarded in this light, the distance to be traversed is certainly not excessive, being probably well within the lasting power of such a balloon as that employed by Andree. If, for the sake of gas supply, Aden were chosen for the starting ground, then 1,200 miles E.N.E. would carry the voyager to Muscat; 1,100 miles N.E. by E. would land him at Sohar; while some 800 miles would suffice to take him to the seaboard if his course lay N.E. It must also be borne in mind that the Arabian sun by day, and the heat radiated off the desert by night, would be all in favour of the buoyancy of the balloon.