"Fire away; as many as you like," rejoined Desmond Blake. "In the first place there is no propeller, that is, if you mean a rotary one. To go back to the simile of birds; they don't cleave through the air under the action of a two-bladed propeller. That, after all, is a tacit admission by aeronautical engineers that they are unable to copy nature; so they make a substitute that fails to perform the relative task that a bird's wings do with seemingly little effort. I have dispensed with a propeller and substituted mechanical planes that approximate very clearly the natural method of flying. Before I explain further we must get aboard; I'll show you the way. One could make use of a pair of steps, but they would be awkward things to carry about, especially at the Front."
With remarkable agility the inventor swarmed up a light aluminium ladder built into the girder-legs of the battleplane. Thirty feet up he disappeared from view through an aperture in the underside of the fuselage.
In a trice Dick followed, Athol ascending with more deliberation. The latter was puzzled at the great rigidity of the aluminium girders. Evidently Desmond Blake had solved the task of making the metal as tough as steel without any marked increase of weight. Another thing Athol noticed was that all the cross sections of the latticed girder were pear-shaped, the blunt end facing the direction of flight, the tapering end being aft. This was expressly for the purpose of reducing the friction of the air.
Squeezing through the trap door the lads found themselves on the floor of the chassis, which was composed of a succession of broad steps on inclined planes in order to afford a firmer footing when the battleplane was at rest. Between the floor and the curved roof or deck there was sufficient space for a tall man to stand upright. Against the concave sides were folded cots, in which those of the crew "off duty" could sleep during prolonged flights, while at approximately one-third of the length of the fuselage from the blunt nose was the motor room, a veritable nest of intricate, lightly-built and powerful machinery.
"Do you work the battleplane entirely from under cover?" asked Athol.
"Oh no," replied Desmond Blake. "It is essential to have a wide field of outlook. Here is the pilot's seat. Get in and see what it is like."
He indicated a circular seat perched about a foot beneath the deck, from which an oval-shaped opening provided with a raised coaming had been cut. Overhead was a light metal canopy which, when required, could be lowered flush with the top part of the chassis. To gain the seat from the floor of the fuselage it was necessary to make use of a metal ladder.
"Steady yourself by that horizontal bar," cautioned the inventor, indicating a short rod on the fore side of the coaming.
The warning was necessary, for, as Athol slid into the seat, the seat slid from him. It was only by hanging on to the bar and allowing his feet to dangle in the air that the lad saved himself from falling four or five feet to the floor.
"Don't say that I didn't give you fair warning," exclaimed Desmond Blake, while Dick laughed at his friend's predicament. "Now, have another shot at it. Lift yourself fairly into the seat. That's it."