But the huge craft possessed another novelty besides that of exceptional size. It was provided with a subsidiary balloon, called the "Compensator," and properly the idea of M. L. Godard, the function of which was to receive any expulsion of gas in ascending, and thus to prevent loss during any voyage. The specification of this really remarkable structure may be taken from M. Nadar's own description. The globe in itself was for greater strength virtually double, consisting of two identical balloons, one within the other, each made of white silk of the finest quality, and costing about 5s. 4d. per yard. No less than 22,000 yards of this silk were required, and the sewing up of the gores was entirely done by hand. The small compensating balloon was constructed to have a capacity of about 3,500 cubic feet, and the whole machine, when fully inflated, was calculated to lift 4 1/2 tons. With this enormous margin of buoyancy, M. Nadar determined on making the car of proportionate and unparalleled dimensions, and of most elaborate design. It contained two floors, of which the upper one was open, the height of all being nearly 7 feet, with a width of about 13 feet. Then what was thought to be due provision was made for possible emergencies. It might descend far from help or habitations, therefore means were provided for attaching wheels and axles. Again, the chance of rough impact had to be considered, and so canes, to act as springs, were fitted around and below. Once again, there was the contingency of immersion to be reckoned with; therefore there were provided buoys and water-tight compartments. Further than this, unusual luxuries were added, for there were cabins, one for the captain at one end, and another with three berths for passengers at the other. Nor was this all, for there was, in addition, a larder, a lavatory, a photographic room, and a printing office. It remains now only to tell the tale of how this leviathan of the air acquitted itself.