Billy's mania was astronomy. He would spend the hours of his playtime lying on his stomach with a map of the stars spread out before him on the floor. Billy was a great astronomer--in secret. On the very day when he and I were being initiated into the mysteries of Decimals, he whispered to me in class, "I say, I wonder how people found out the weight of the planets." He was an absent-minded boy, and many a clout on the head did he receive at this time for paying no attention to what was going on in class. Little did the master know what Billy was thinking of as he stared at the wall before him with his great, dreamy eyes--and not for ten thousand worlds would Billy have told him. He was thinking about the weight of the planets, and the problem lay heavy on his soul; and Billy grew ever more absent-minded, and spent more time on his stomach every day. At last he suddenly waked up and began to get top-marks not only in Arithmetic but in every other subject as well. And later on, when we came to the Quadratic Equations and the Higher Geometry, the master was amazed to find that Billy required no teaching at all. "What has happened to Billy?" asked somebody; and the answer came, "Why, of course, Billy has _burst_." So he had. Billy had found out "how they weighed the planets," and the mass of darkness that oppressed him had been blown away in the explosion. About the same time I burst also. On counting up my tickets I found there were ten thousand of them. Then came a pause, during which Billy and I wandered about in dry places seeking rest and finding none. Life lost its spring and the world seemed very flat, stale, and unprofitable. Conversation flagged, or became provocative of irritable rejoinders. "I say, what are you going to do with all those tramcar tickets?" asked Billy one day. "Oh, shut up!" I replied. Shortly afterwards it was my turn. "Billy, tell me what they mean by 'sidereal time.'" "Oh, shut up!" said he. We were both waiting for the new birth, or the new explosion, utterly unconscious of our condition. But the Powers-that-be were maturing their preparations, and, all being complete, they put the match to the train in the following manner. The usual exchange of measles and whooping-cough had been going on in our school, and Billy and I being convalescent from the latter complaint, to which we had both succumbed at the same time, were sent out one day to take an airing in the Park. On passing down a certain walk, shaded by planes, we noticed a very old gentleman seated in a bath-chair which had been wheeled under the shadow of one of the trees. He sat in the chair with his head bent forward on his chest, and his wasted hands were spread out on the cover. He seemed an image of decrepitude, a symbol of approaching death. He was absolutely still. A young woman on the bench beside him was reading aloud from a book.