"In the nearly thirty years of the existence of the Geological Survey, as a separate branch of the Department of the Interior," replied Field, "during which time explorations of the most extreme peril have been undertaken, only one life has been lost. Really, when you come to consider how much of the work has been done in lands absolutely unknown, and that thousands of miles of territory have been covered wherein a white man had never before set his foot, this is nothing short of astounding." "But if sickness should strike a camp?" queried the boy. "Hard work, clean living, good judgment, and the open air, are worth all the drugs we know about and a whole lot more that we don't. Of course a small chest of certain radical remedies accompanies each party, with quinine and things like that, but it is seldom that it is opened." "But how about accidents, Mr. Field?" "Such as?" "Breaking a leg by a fall, or something like that," the boy responded. "I don't see what business any man on the Survey has to fall. That isn't what he's there for. He's there not to fall. Personally, I have never had any accidents which would need other than ordinary attention, nor have I had any with any members of my party. Then an injury would have to be pretty bad, any way, that couldn't wait until some kind of a doctor was reached, that is unless it was in the north of Alaska, or some place like that, and in such trips a little surgical case is sent along, and the chief would do as well as he could do with it." "Then," said Roger with a short laugh, "I'm just as glad that I'm not at the bottom of the quag, for your sake as well as my own, for I should hate to be the one to spoil the Survey's record." But while Roberts was expected in camp shortly, a couple more weeks rolled away before the party, completing its line through a very difficult piece of marsh, headed for one of the famous corduroy roads and made its way back to headquarters. There, with one of the farmer's children on his knee and the others grouped around him sat Roberts, occupied apparently in telling some interesting story or fairy tale. He put down the youngster and shouted as the party hove in sight. The chief was delighted without question to see the newcomer, for while he had been greatly pleased with Roger, the boy could not be expected to be as valuable as an experienced man, and was not to be depended on to proceed in his work without instruction and supervision. "I was looking for you a couple of weeks ago, Mr. Roberts," he said. "I expected to be here earlier, Mr. Field," answered the other, "but Mr. Herold asked me to put in a few days in that Susquehanna flow-measurement business, and that put me back." Roger looked inquiringly at his chief, who catching his look of question, said, "Well, son?" "I would like to ask," said the boy hesitatingly, "what that stream flow-measurement is for?"