~Gas bags.~--These are of great strength and of unusual shapes, made to fit the interior, which is encumbered with cross stays. All but two of the bags are always full, and when the gas expands it flows into the remaining two, which are nearly empty at sea level, and full at 6500 feet (2,000 m.) A centrifugal pump is used for distributing the gas. There are 14 gas bags. ~Motors.~--2 Maybach of 270 h.p. each. The propellers are at the ends of the car, driven through 1 set of reduction gear. ~Speed.~--38-43 m.p.h. About 59-64 k.p.h. ~Propellers.~--2 aft. Also 1 with its axis vertical. ~Steering.~--Vertical and horizontal rudders at both ends of the ship. Also see Propellers. Remarks.--Two of these ships were under construction, and one was to be presented and one sold to the German government. The hull is built of special 3-ply wood made of Russian white fir; this wood is pressed into channel bars, angle bars, and all other requisite shapes. The strength of the hull is such that it can be supported at the ends without damage; its lightness is such that although the ship is nearly half as large again as _Zeppelin II_, yet the hull weighs about 3 tons less. Designed by Prof. Schuette. In 1910, structural defects were found in _Schuette I_ when the loads were applied. This has necessitated extensive alterations and much delay. In 1911 it was completed, and sold for L25,000 to the German Army. SCHUeTTE-LANZ 2. Military. S.L. II. (1913.) +------------------------------+ | | | _Building._ | | Enlarged edition of above. | | 918,000 c. feet (26,000 m cubed.) | | | +------------------------------+ ZEPPELIN type. Rigid. Graf von Zeppelin, Friedrichshafen. The features of this type are--A rigid framework of aluminium, a number of drum-shaped gas bags, and a thin outer cover. [Illustration] At the end of March, 1913, the total of _Zeppelins_, limit and building was 16, including one (number 18) for Austria. Of these several had come to grief in various ways, and the actual total at the date mentioned, was:-- ~8 effective~ = 4 Army (of which one _Z4_ was still on trials), 1 naval and 3 private. 3 completing or building = 1 naval, 1 private and 1 for Austria. Others projected but not actually in hand. All are on the lines of the above plan, differing only in minor details, such as the provision of a cabin amidships, etc., and in dimensions. Details see the following pages.