I did so, and then handed it back to the agent.
"Look," he cried, "as soon as you cease reading, the fluid sinks back to zero. But the little aluminum arrow remains at the highest point which the fluid reached—that is, the highest point of interest which you felt in the book. Ah, yes—40 degrees—a faint interest. You will notice that the degree-points are marked at intervals with descriptive phrases—40 is 'faint interest,' 30 is 'indifference,' 20 is 'would not keep you awake after 9 p.m.,' and so on."
The thing was very fascinating.
"It is astounding," I said, "for that is exactly my feeling towards Junius, and yet I tried to get more interested in him than usual."
The agent laughed.
"You can't fool the gauges," he said. "You can't do it, even when you know one is attached to your book. I need not say that it is absolutely correct when the reader is not aware that there is a gauge upon his book. You must see the value of these to a librarian. Let me show you how incorruptible they are. Have you something there in which you have absolutely no interest—some book or article that is dry as dust?"
I looked about.
"This pretty nearly fills the bill," I said, and I handed him a copy of a library magazine with an article by Dr. Oscar Gustafsen on "How to Make the Workingman Read the Greek Tragedies."
The agent attached an interest gauge, and told me to read Dr. Gustafsen's article, and to try as hard as I could to become interested; to pretend, if I could not feel, the greatest excitement over it. I did so, and strained every muscle in my brain, so to speak, to find something in it to interest or attract me. It was no use—the fluid gave a few convulsive wabbles, but at the end the little arrow had not even reached 10, or "Bored to Death."
Then the agent took a copy of "The Doctor's Dilemma," and putting an interest gauge on the volume, asked me to read a few pages, and to remain as indifferent as possible. I read it calmly enough, but the liquid in the tube mounted slow and sure, and when we examined the arrow it pointed to 80.