"After an egg is laid, a chemical change begins to take place, and more or less gas is formed. This gas finds its way to the large end, and as the decomposition increases the egg becomes lighter at the heavy end, and finally enough gas is evolved to bring it to the surface."
Fig. 15. Testing Eggs
The most important work on hand was the construction of the addition to their home. After considering the matter in all its details, it was concluded to put up a building entirely separate from the other structures, to contain four rooms, one of them to be large and utilized as a common living room, and the others as sleeping apartments.
The material had been taken out for the building, and the Professor, John, George and Ralph were engaged at this work, while Harry and Tom were engaged in the machine shop and were busy in turning out the barrels for new guns, as well as preparing the ammunition.
The tools in the machine shop were not numerous enough to advantageously utilize more of them there, and the building was now very important to them, as the four boys were compelled to sleep in the shop, for want of room in the house.
The joist had all been laid for the lower floor and the studding now being put up and the upper joist laid on preparatory to erecting the rafters. John was an expert in building, and was really the directing hand at the various steps in the operation. While engaged in the drawing up of the rafters, one of the floor pieces gave way, and John was precipitated to the floor below, striking as he fell one of the lower joist, which cut a terrible gash in his head and rendered him unconscious.
The Professor rushed over to the fallen man, and the boys were on the spot to render assistance. Chief, who was also an interested worker, was the first to grasp him with his powerful arms, and disdaining the assistance of the others, carried him to the house and gently laid him down, as the Professor directed.
Without a word he rushed for the jar of water and brought it to the Professor, who bathed his wounds, but the blow was so severe that he exhibited no signs of returning consciousness.
Harry and Tom rushed over to the house in consternation, and exhibited the greatest grief.