1. The airship was to be capable of carrying out the duties of an
aerial scout.

2. She was to be able to maintain a speed of 40 knots for
twenty-four hours, if possible.

3. She was to be so designed that mooring to a mast on the water
was to be feasible, to enable her to be independent of her
shed except for docking purposes, as in the case with surface
vessels.

4. She was to be fitted with wireless telegraphy.

5. Arrangements were to be made for the accommodation of the crew
in reasonable comfort.

6. She was to be capable of ascending to a height of not less
than 1,500 feet.

These conditions rendered it necessary that the airship should be
of greater dimensions than any built at the time, together with
larger horse-power, etc.

These stipulations having been settled by the Admiralty, the
Admiralty officials, in conjunction with Messrs. Vickers Ltd.,
determined the size, shape, and materials for the airship
required. The length of the ship was fixed at approximately 500
feet, with a diameter of 48 feet. Various shapes were
considered, and the one adopted was that recommended by an
American professor named Zahm. In this shape, a great proportion