This hood was of a waterproof silk, coated with powdered aluminum, that metal being used because of its semi-incombustibility. This silk also covered the sides of the central compartment, making a wind-, rain- and waterproof cabin. The lookout windows on all four sides were covered with isinglass. The bottom of the framework of the car forward and aft of the engine compartment had a ladder-like flooring of spruce, inserted more for strengthening the car than for service. But on top of the car, reaching from end to end, was a continuous runway two feet wide which could be used in hurriedly visiting either propeller or rudder. This runway was protected by guide ropes of Italian hemp running through posts extended upward from the sides of the car. The top of the engine compartment was completely floored, making a platform 6 x 6.12 feet square. This was surrounded by a protecting network, and Alan named it the "bridge."
A light rope-ladder extended into the engine cabin from an opening in the roof, making the top floor space or bridge and the upper runways quickly accessible. The gasoline reservoir, just forward of the engine, was connected with the bridge by a copper supply pipe. The extra supply of gasoline was to be carried on the bridge in the open air, and lashed to the netting instead of being stored in permanent reservoirs as is the usual practice. This was in order that the empty vessels might be thrown overboard when it was necessary to lighten the balloon.
The other sections of the car were each 8 feet long and decreasing in height from 6 feet next the cabin to 5 feet at the end of the car. In the two sections just forward of the cabin and in the two just aft provision had been made for attaching the eight liquid hydrogen casks—four at each end. As this liquid was reconverted into gas the light sheet-iron casings might likewise be cast overboard to lighten the balloon. As needed, the liquid hydrogen jars, coated with mercury, were to be taken from their casings and carried to the bridge where the reconverter was located.
Aft of the engine cabin was the store room for water and provisions. The grooves and rods for the counterweights and equilibrium adjuster ran in the middle of the upper footway and the propeller shaft rested on the bottom of the forward section of the car.
At ten o'clock that evening all the work on the car was finished except the buckling on of the aluminum silk sides and the hanging of the propeller, the rudder and the aeroplane sides. It was as long and as hard a day's work as either of the boys had ever done. They were dead tired, but happy, and after a sousing wash-up they got into their pajamas and, throwing their blankets on the floor of the little office, were soon fast asleep.
CHAPTER XV
HOW JACK JELLUP LOST AN ARM
In spite of his fatigue Ned did not sleep soundly. It had been threatening a thunder storm all evening and the increasing oppressiveness of the air made the young, aeronaut wakeful. The long whistle and jarring stop of the midnight local train finally fully aroused him. In the west the thunder was rumbling and great sheets of heat lightning promised a storm in a short time. After slipping out into the corral and seeing that the waterproof silk sides of the car were securely buttoned around the engine Ned returned and again tried to go to sleep.
But his restlessness continued. In his early sleep he had had a vivid dream about the wagon expedition. In this he thought that Marshal Jack Jellup had followed Elmer, Bob and Buck and set fire to the wagons while his friends were asleep in camp. It was a relief to awaken and find that the flash of light was lightning and not, as he had imagined in his dream, an explosion of the gasoline carried in Buck's big wagon. He lay awake awhile regretting the quarrel with Jellup, and then he sank into a doze again.