The third system, that of mooring to a mast, possesses several features peculiar to itself, and not embraced by the other two, which should secure it prolonged investigations. The system is by no means new and has been tried from time to time for several years, but since the question of mooring in the open has been so ventilated and is now considered of such vital importance, these experiments have been continued, and in less spasmodic fashion than in the past. In a trial with a small non-rigid airship some months ago a signal success was achieved. The ship remained attached to a mast in open country with no protection whatsoever for six weeks in two of the worst months of the year. During this period two men only were required to look after the ship, which experienced gales in which the force of the wind rose to 52 miles per hour, and not the slightest damage was sustained. Two or three methods of attaching the airship to the mast have been proposed, but the one which appears to be most practical is to attach the extreme bow point of the ship to some form of cap, in which the nose of the ship will fit, and will revolve round the top of the mast in accordance with the direction of the wind. For large airships, employed as passenger and commerce carriers, we can imagine the mast advanced a stage further, and transformed into a tower with a revolving head. Incorporated in this tower will be a lift for passengers and luggage, pipes also will be led to the summit through which both gas and water can be pumped into the ship. With the airship rigidly held at the head of such a structure all the difficulties of changing crews, embarking and disembarking passengers, shipping and discharging cargo and also refuelling, vanish at once. Assuming the mooring problem solved with success, and we feel correct in this assumption, the first two of our difficulties automatically disappear. Sheds will only be necessary as repair depots and will not be extensively required, all intermediate stopping places being provided with masts and necessary arrangements for taking in gas, etc. At these intermediate stations the number of men employed will be comparatively speaking few. At the depots or repair stations the number must, of course, be considerably increased, but the provision of an enormous handling party will not be necessary. At present large numbers of men are only required to take a large airship in or out of a shed when the wind is blowing in a direction across the shed; when these conditions prevail the airship will, unless compelled by accident or other unforeseen circumstances, remain moored out in the open until the direction of the wind has changed.