which somewhat made up for
the absence of springs, and Eradicate was their driver. Tom had made
this arrangement so they might talk among themselves without fear of
being overheard by the Mexicans. At first Senor Delazes had
suggested that one of his own drivers pilot Tom's cart, saying:

"I know what the senors fear--that their language may be listened
to, but I assure you that this man understands no English, do you,
Josef?" he asked the man in question, using the Spanish.

The man shook his head, but a quick look passed between him and his
employer.

"Oh, I guess we'll let Rad drive," insisted Tom calmly, "it will
remind him of his mule Boomerang that he left behind."

"As the senor will," Delazes had replied with a shrug of his
shoulders, and he turned away. So it was that Tom, Ned and Mr.
Damon, in their own cart, piloted by the colored man, were in the
rear of the little cavalcade.

"Have you any idea where you are going, Tom?" asked Ned, after they
had reached the shade, when it was not such a task to talk.

"Oh, I have a good general idea," replied the young inventor. "I've
studied the map Mr. Illingway sent, and according to that the city
of--well, you know the place we're looking for--lies somewhere
between Tampico and Zacatecas, and which the plain of the ruined
temple which used to be near the ancient city of Poltec, is about a
hundred and fifty miles north of the city of Mexico. So I'm heading
for there, as near as I can tell. We ought to fetch it in about a
week at this rate."

"And what are we to do when we get there?" inquired Mr. Damon. "If
we keep on to that place where the images are to be found, with this
rascally crew of Mexicans, there won't be much gold for us." He had
spoken in low tones, though the nearest Mexican cart was some
distance ahead.

"I don't intend to take them all the way with us," said Tom. "When I
think we are somewhere near the temple plain I'm going to make the
Mexicans go into camp. Then we'll put the balloon together and we
four will go off in that. When we find what we're looking for we'll
go back, pick up the Mexicans, and make for the coast."

"If the head-hunters let us," put in Ned grimly.

"Bless my nail file! There you go again!" cried Mr. Damon.
"Positively, Ned, you get on my nerves."

"Yais, Massa Ned, an' _I_ jest wish yo' wouldn't mention dem head
gen'men no mo'," added Eradicate. "I can't drive straight when I
hears yo' say dem words, an' goodness