and only 40 open to the sea; therefore the chances of coming upon land at _any one_ part of this zone is as 320 to 40; but with a choice of points for descent such as the aeronauts would have unless the wind blew precisely down the axis of the opening, the chances would be far greater. If the wind continued as at starting, they would be blown to Finland; a westerly deflection would land them in Siberia, easterly in Norway; a strong E. wind at the later stage of the trip would blow them back to Greenland. In all the above I have supposed the aeronauts to be quite helpless, merely drifting at random with that portion of the atmosphere in which they happened to be immersed. This, however, need not be the case. Within certain limits they have a choice of winds, owing to the prevalence of upper and lower currents blowing in different and even in opposite directions. Suppose, for example, they find themselves N. of Spitzbergen, where “Parry’s furthest” is marked on some of our maps, and that the wind is from the N.E., blowing them towards the Atlantic opening. They would then ascend or descend in search of a due N. or N. by W. wind that would blow them to Norway, or W.N.W. to Finland, or N.W. to Siberia, or due E. back to Greenland, from whence they might rejoin their ships. One or other of these would almost certainly be found. A little may be done in steering a balloon, but so very little that small reliance should be placed upon it. Only in a very light wind would it have a sensible effect, though in case of a “near shave” between landing, say at the Lofodens or Iceland, and being blown out to sea, it might just save them. As already stated, Commander Cheyne believes in the possibility of returning to the ship, and bases his belief on the experiments he made from winter quarters in Northumberland Sound, where he inflated four balloons, attached to them proportionately different weights, and sent them up simultaneously. They were borne by diverse currents of air in _four different directions according to the different altitudes_, viz., N.W., N.E., S.E., and S.W., “thus proving that in this case balloons could be sent in any required direction by ascending to the requisite altitude. The war balloon experiments at Woolwich afford a practical confirmation of this important feature in aerostation.” Cheyne proposes that one at least of the three balloons shall be a rover to cross the unknown area, and has been called a madman for suggesting this merely as an alternative or secondary route. I am still more lunatic, for I strongly hold the opinion that the easiest way for him to return to his ship will be to drift rapidly across to the first available inhabited land, thence come to England, and sail in another ship to rejoin his messmates; carrying with him his bird’s-eye chart, that will demonstrate once for all the possibility or impossibility of circumnavigating Greenland, or of sailing, or sledging, or walking to the Pole.