One afternoon Tom was alone in the shop, for he had sent Koku
on an errand, and Eradicate was off in a distant part of the
grounds, doing some whitewashing, which was his specialty. Ned
had not come over, and Mr. Swift, having gone to see some
friends, and Mrs. Baggert being at the store, Tom, at this
particular time, was rather isolated.

He was conducting some delicate electrical experiments, and to
keep the measuring instruments steady he had closed all the
windows and doors of his shop. The young inventor was working at
a bench in one corner, and near him, standing upright, was a
heavy shaft of iron, part of his submarine, wrapped in burlap,
and padded, to keep it from rusting.

"Now," said Tom to himself, as he mixed two kinds of acid in a
jar, to produce a new sort of electrical current, "I will see if
this is any better than the first way in which I did it."

He was careful about pouring out the powerful stuff, but, in
spite of this, he spilled a drop on his finger. It burned like
fire, and, instinctively, he jerked his hand back.

The next instant there was a series of happenings. Tom's elbow
came in contact with another jar of acid, knocking it over, and
spilling it into the retort where he had been mixing the first
two liquids. There was a hissing sound, as the acids combined,
and a thick, white vapor arose, puffing into Tom's face, and
making him gasp.

He staggered back, brushed against the heavy iron shaft in the