Campmates: A Story of the Plains

by Kirk Munroe

"Now what do you think of running a line across the desert ahead of us?" continued the chief-engineer; "are you as anxious to undertake that as you were to cross Arizona?"

"Yes, indeed, I am, sir," replied Glen, earnestly. "I am anxious to go wherever the second division goes; and if anybody can get a line across that desert, I know we can."

"I believe you can," said the chief, smiling at the boy's enthusiasm, "and I am going along to see how you do it."

The Colorado was so broad, deep, and swift that Glen wondered how they were going to measure across it, and had a vague idea that it could be done by stretching a long rope from bank to bank. He asked "Billy" Brackett; and when the leveller answered, "By triangulation, of course," Glen showed, by his puzzled expression, that he was as much in the dark as ever.

"You have studied geometry and trigonometry, haven't you?" asked the leveller.

Glen was obliged to confess that, as he had not been able to see the use of those studies, he had not paid much attention to them.

"Well, then, perhaps you'll have a better opinion of old Euclid when you see the practical use we'll put him to to-morrow," laughed "Billy" Brackett.

Glen did see, the next day, and wondered at the simplicity of the operation. The front flag was sent across the river in a boat, and on the opposite side he drove a stake. While 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.