he was thus engaged, a line a
quarter of a mile long was measured on the bank where the rest of the
party still remained, and a stake was driven at each end of it. The
transit was set up over one of these stakes, and its telescope was
pointed first at the other and then at the one across the river, by
which means the angle where it stood was taken. It was then set over the
stake at the other end of the measured line, and that angle was also
taken. Then Mr. Hobart drew, on a leaf of his transit-book, a triangle,
of which the base represented the line measured between the two stakes
on his side of the river, and one side represented the distance across
the river that he wished to find. He thus had one side and two angles of
a triangle given to find one of the other two sides, and he solved the
problem as easily as any boy or girl of the trigonometry-class can whose
time in school has not been wasted as Glen Eddy's was.

It was a simple operation, and one easily performed, but it involved a
knowledge of the four fundamental rules of arithmetic, of proportion, or
the rule of three, of geometry, of trigonometry, and of how to use a
surveyor's transit; all of which, except the last, are included in the
regular course of studies of every boy and girl in America who receives
a common-school education.

Glen had also been sent across the river, where he held his rod so high
up on the bank that the cross hair in the telescope of the level cut
just one tenth of an inch above its bottom. Then, when "Billy" Brackett
came over, and went on beyond Glen, he set the level up so high on the
bank that, through it, he could just see the top of the rod, extended to
its extreme length. So they climbed slowly up out of the Colorado
Valley, and began to traverse the dreary country that lay between it and
the Sierra Nevada.

For the first hundred miles or so they got along very well, so far as
water was concerned, though the mules and horses speedily began to grow
thin and weak for want of food. The patches of grass were very few and
far between, and the rations of corn exceedingly small; for in that
country corn was worth its weight in gold, and scarce at that.

Chapter XXXVIII.

DYING OF THIRST IN THE DESERT.

Matters were bad enough by the time Mr. Hobart's party reached Camp
Cady, nearly half way across the desert; but, from there on, they became
much worse. The line could no longer follow the winding government
trail, but mu