"Besides," I added, "he did not offer to put us up at his clubs or in any way behave like a gentleman."

Knowlton grinned his favourite grin.

"Ted, I hadn't thought of that as an index of Norwood's business ability, but damned if I don't think your reason as good as mine."

With that he pressed a button on his desk and a spotlessly clean young woman responded.

"Bring me the file of our customers," he said, and she withdrew.

"What shall I do?" I asked.

"You—oh, yes—you go out to the drafting room and design the testing laboratory. Come to me if you get stuck on any details. As for me," he added, "I'm going to start looking for that Senegambian this very minute."

My arrival in the drafting room caused a mild sensation among its occupants, but a drawing table, desk, instruments, and materials were speedily placed at my disposal, and as there was a rule against talking in this room, I was left in silence, but under close observation, to work out my problem. Furtively I produced from my pocket a useful manual containing practical tables and formulae for nearly everything under the sun, and with the help of this and my actual knowledge of what a chemical laboratory ought to contain, I had made considerable progress with my rough pencilled plan when the twelve-o'clock whistle blew. I had become so absorbed in my work that I had forgotten all about the noon hour.

I found Knowlton in the office where I had left him. He was surrounded by piles of papers and correspondence which he was reading, checking, and making notes about on separate slips of paper.

"Not found him yet, but I think I'm on his trail, Ted. Let's go to lunch."