By continually observing the planet during ensuing seasons, a marked decrease in the size of the polar caps during the Martian summers was noted, with a corresponding darkening of the “canals”, as Professor Palmer designated the lines. The spots, or terminals, he called “oases.” His deductions were, that owing to the admitted scarcity of water on the arid planet, the Martians transported water from the vast, melting polar snows by means of canals. It was this question of canals, and the much mooted question of sufficient heat to sustain life on the small planet, which caused contention between the two renowned experts. 2 Despite many years of concentration on technical things, Professor Palmer was a surprisingly human and ordinary-appearing man. The fact that he was considered one of the world’s foremost authorities on astronomy, and was a lecturer of world-wide renown, did not detract from his naturally benign disposition. Yet there was something compelling about his personality. Students before whom he delivered lectures accorded him marked attention, and went away with a graphic picture in their minds of the things he wished to convey to them. “Henry,” he remarked quizzically to his young but capable secretary one morning, having just read a particularly seathing criticism of his pet theories, “these gentlemen at least take my hobby seriously. That in itself convinces me that my deductions are worthy of consideration.” “They take advantage of the fact that you have no means of definitely proving your deductions,” defended Henry, loyally. “As you have remarked, even Columbus was ridiculed; but he, at least, had means of obtaining concrete proof to silence the scoffers.” “Well put, my friend. A few more earnest advocates of my theories like yourself, and I should require no proof.” “That reminds me,” resumed the grateful Henry G. Simms, “there was a young chap in here yesterday who claimed to be an ardent champion of your views. He was extremely anxious to see you. Said he had a matter of great importance to take up with you.” “He’ll return?” “Grant’s army couldn’t keep him away. He will be here at 10 o’clock.” “So? What sort of a chap is he?” curiously. “A well set-up fellow of about twenty-four. About six feet tall; light hair, pleasant features, refined manners. Impetuous sort of fellow.” That was how Robert Sprague happened to meet Professor Palmer a half hour later. A pleasant thrill possessed him as he shook hands with the professor. The kindly, though keen, gray eyes met his encouragingly. This was contrary to Robert’s expectations, for he had assumed that he would be fortunate if he succeeded in seeing so busy and prominent a man for a few minutes. He was prepared even for a curt dismissal. What he did not know was that his evident earnestness and enthusiasm had obtained for him an interview through the redoubtable Henry where others would have failed.