"What—what's that?" gasped Tom, coughing and sneezing.
"Some chemical—I—I don't know what kind," spluttered Mr. Jackson. "Have you any carboys of acid in there Tom, that might have exploded by the heat?"
"No; not a thing. Let's try again."
Once more they tried to go in, but were again driven back by the distressing fumes. The fire was eating down, now. There was a hole burned in the roof, and by the leaping tongues of flame Tom could see his aeroplane. It was almost in the path of the blaze.
"We must get her out!" he shouted. "I'm going in!"
But it was impossible, and the daring young inventor nearly succumbed to the choking odors. Mr. Jackson dragged him back.
"We can't go in!" he cried. "There has been some mysterious work here! Those fumes were put here to keep us from saving the machine. This fire has been set by some enemy! We can't go in!"
"But I am going!" declared Tom. "We'll try the back door."
They rushed to that, but again were driven out by the gases and vapors, which were mingled with the smoke. Disheartened, yet with a wild desire to do something to save his precious craft, Tom Swift drew back for a moment.
As he did so he heard a hiss, as Eradicate turned the chemical stream on the blaze. Tom looked up. The faithful colored man was on a ladder near the burning roof, acting well his part as a fireman.