Along a meridian traced on the envelope coloured marks are made, with figures indicating every 546 yards of cubic contents of the segment above each mark. This will admit of the progress of inflation at Spitzbergen being rapidly ascertained. On two other meridians, suitably situated, are shown the positions for the straps to support the sails with which the polar balloon is to be provided. THE CAR.—In the construction of the car, the use of iron or steel was prohibited, so as to avoid interfering with the action of the magnetic instruments. Its form is cylindrical, measuring two metres in diameter, from centre to centre of its sides, which are of cane basket-work mounted on a framework of chestnut-wood; eight handles of wicker-work are attached to the cylindrical part, at a convenient height, to facilitate the transport. The bottom is strengthened by wooden crossbeams placed externally and fastened to the basket-work by bolts and brass plates put on the inside. The cylindrical part is truncated on one side, having a plane surface which is to form part of an inclined plane intersecting the lower floor of the car, and extending from this floor to midway up the cylinder, the length of the chord formed by the plane intersecting the base being 51 inches. When the balloon touches the ground, rolling of the car will be avoided by this flat surface, which will rest and drag on the ground. Internally, the upper margin of the side is fitted all round with about 100 cords terminating in buckles or eyes. To these cords, which are passed through the basket-work, instruments and various objects are to be attached. The roof of the car is a disc or cover, likewise of basket-work, slightly convex in order to prevent any accumulation of water. The margin of the periphery of this cover forms a cavity into which the margin of the car is inserted, thus preserving its peculiar shape. Cross-pieces of wood fixed inside the cover or roof impart to it the necessary rigidity to support the observers; entrance to the car and exit therefrom is effected by means of a trap-door which moves on hinges. Above the flattened part, the cylindrical side of the car is fitted with two square windows with glass panes of 5¾ inches side; the bottom of the car has two square openings of 7⅘ inches side, closed by wooden trap-doors. The car is covered with tarpaulin having openings corresponding to those in the basket-work. The tarpaulin of the roof forms a vertical rim 3⁹⁄₁₀ inches in width, perforated with holes for draining off rain-water. The car is suspended by six hemp ropes 1¹⁄₁₀ inch thick. Their respective strength is from 17,636 lbs. to 19,841 lbs. They are interwoven with the basket-work, and joined together at the bottom of the car by a hexagon of rope. [Illustration: START OF THE VIRGO FROM GOTHENBURG, 7TH OF JUNE, 1896.]