“I couldn’t prove that it isn’t,” said David.

“All right; neither can I. But on this very point we’re continually having trouble with the railroad people, as you know. We may admit cheerfully that we don’t know quite all there is to be known about concrete; but neither do the railroad company’s engineers. Their inspectors on this bridge are a bunch of cranks; that is the sort of fault-finders that the ‘party of the first part’ always hires to put on the job to watch the contractors. If we lived up to the specifications as they’d like to make us, the Grillage Engineering Company would come out about a mile deep in the hole.”

Again David Vallory acquiesced. From time to time he had had troubles of his own with the watch-dog inspectors representing the railroad company for which the bridge was being constructed.

“You younger fellows are fresh from the laboratories, and you have the latest word in the testing experiments,” said Grimsby. “That’s why I’ve called you in for a conference. You’ve been following the cement tests made in our field laboratory, haven’t you?”

“Most of them; yes.”

“Well, you haven’t seen anything wrong with the stuff, so far, have you?”

“Never.”

The bearded chief nodded. “That’s the talk,” he said; then he made his frontal attack without further preface. “You are loyal to your salt, aren’t you, Vallory? If what they tell me about you and Mr. Grillage is true, you ought to be.”

“I hope I am,” returned the loyalist, a little at a loss to prefigure what was coming next. Then he added: “My family owes Mr. Grillage a greater debt than we can ever hope to pay, if that is what you mean.”

“So I’ve understood. Now we can get down to the nub of the thing. You’ve heard that the railroad company has hired a new chief engineer, haven’t you?”