"Yes."
"Now you need this much science to prevent your bluff from getting you into trouble. When you attempt to bluff a scientific man be sure not to bluff along the line of his knowledge and the line of your ignorance. By the way, when do you want that operation performed?
"The sooner the better," Irving replied.
"How about now?"
This almost took the boy's breath away, but after a few minutes he answered:
"That's all right, I suppose, but I'd better call up my office first and tell the boss what's doing."
"Very well; here's a telephone. Call him up."
Irving did so and in a few minutes had authority to "go ahead and have it over as soon as possible."
CHAPTER XXXV
THE TAPPING ON THE WINDOW