But if Tait's science weighs him to the earth, he has a genius for sticking to his subject, and I am lost in admiration every time I bring back his lectures. It comes as natural to his old students to say when they meet, "What a lecturer Tait was!" as to Englishmen to joke about the bagpipes. It is not possible to draw a perfect circle, Chrystal used to say, after drawing a very fine one. To the same extent it was not possible for Tait never to fail in his experiments. The atmosphere would be too much for him once in a session, or there were other hostile influences at work. Tait warned us of these before proceeding to experiment, but we merely smiled. We believed in him as though he were a Bradshaw announcing that he would not be held responsible for possible errors. I had forgotten Lindsay--"the mother may forget her child." As I write, he has slipped back into his chair on the professor's right, and I could photograph him now in his brown suit. Lindsay was the imperturbable man who assisted Tait in his experiments, and his father held the post before him. When there were many of us together, we could applaud Lindsay with burlesque exaggeration, and he treated us good-humoredly, as making something considerable between us. But I once had to face Lindsay alone, in quest of my certificate; and suddenly he towered above me, as a waiter may grow tall when you find that you have not money enough to pay the bill. He treated me most kindly; did not reply, of course, but got the certificate, and handed it to me as a cashier contemptuously shovels you your pile of gold. Long ago I pasted up a crack in my window with the certificate, but it said, I remember, that I had behaved respectably--so far as I had come under the eyes of the professor. Tait was always an enthusiast.