I have missed it many and many a time since I came into this war. It is filled with the most beautiful problems, Dick, questions which will take many a good man a whole night to solve. When I think of the joyous hours I've spent over it some of the tenderest chords in my nature are touched."

Pennington uttered a deep groan and buried his face in the grass. Then he raised it again and said mournfully:

"Let's make a solemn agreement, Dick, to watch over our poor comrade. I always knew that something was wrong with his mind, although he means well, and his heart is in the right place. As for me, as soon as I finished my algebra I sold it, and took a solemn oath never to look inside one again. That I call the finest proof of sanity anybody could give. Oh, look at him, Dick! He's studying his blessed algebra and doesn't hear a word I say!"

Warner was buried deep in the pages of a plus b and x minus y, and Dick and Pennington, rising solemnly, walked noiselessly from the presence around to the other side of the little opening where they lay down again. The bit of nonsense relieved them, but it was far from being nonsense to Warner. His soul was alight. As he dived into the intricate problems memories came with them. Lying there in the Southern thickets in the close damp heat of summer he saw again his Vermont mountains with their slopes deep in green and their crests covered with snow. The sharp air of the northern winter blew down upon him, and he saw the clear waters of the little rivers, cold as ice, foaming over the stones. That air was sharp and vital, but, after a while, he came back to himself and closed his book with a sigh.

"Pardon me for inattention, boys," he said, "but while I was enjoying my algebra I was also thinking of old times back there in Vermont, when nobody was shooting at anybody else."

Dick and Pennington walked solemnly back and sat down beside him again.

"Returned to his right mind. Quite sane now," said Pennington. "But don't you think, Dick, we ought to take that exciting book away from him? The mind of youth in its tender formative state can be inflamed easily by light literature."

Warner smiled and put his beloved book in his pocket.

"No, boys," he said, "you won't take it away from me, but as soon as this war is over I shall advance from it to studies of a somewhat similar nature, but much higher in character, and so difficult that solving them will afford a pleasure keener and more penetrating than anything else I know."

"What is your greatest ambition, Warner?" asked Pennington. "Do you, like all the rest of us, want to be President of the United States?"

"Not for a moment. I've already been in training several years to be president of Harvard University. What higher place could mortal ask? None, because there is none to ask for."

"I can understand you, George," said Dick. "My great-grandfather became the finest scholar ever known in the West. There was something of the poet in him too. He had a wonderful feeling for nature and the forest. He had a remarkable chance for observation as he grew up on the border, and was the close comrade in the long years of Indian fighting of Henry Ware, who was the greatest governor of Kentucky. As I think I've told you fellows, Harry Kenton, Governor Ware's great-grandson and my comrade, is fighting on the other side."

"I knew of the great Dr. Cotter long before I met you, Dick," replied Warner. "I read his book on the Indians of the Northern Mississippi Valley. Not merely their history and habits, but their legends, their folk lore, and the wonderful poetic glow so rich and fine that he threw over everything. There was something almost Homeric in his description of the great young Wyandot chieftain Timmendiquas or White Lightning, whom he acclaimed as the finest type of savage man the age had known."

"He and Henry Ware fought Timmendiquas for years, and after the great peace they were friends throughout their long lives."

"And I've studied, too, his wonderful book on the Birds and Mammals of North America," continued Warner with growing enthusiasm. "What marvelous stores of observation and memory! Ah, Dick, those were exciting days, and a man had opportunities for real and vital experiences!"

Dick and Pennington laughed.

"What about Vicksburg, old praiser of past times?" asked Frank. "Don't you think we'll have some lively experiences trying to take it? And wasn't there something real and vital about Bull Run and Shiloh and Perryville and Stone River and all the rest? Don't you worry, George.