“Now, let’s get down to brass tacks,” continued the professor. “This device installed on a large enough scale in the _Sphere_ would make it possible to propel it anywhere in space. The possibilities for research would be virtually boundless. Have you estimated the probable cost of such an apparatus?” “Often. Even with the aid of improved equipment and sufficient workmen, it would require considerable time and a great expenditure. Fifty thousand dollars is a low estimate--and seven months’ time.” Professor Palmer looked thoughtful. Though he was known to be comfortably fixed, his total resources did not quite meet this sum. Slave to science though he might be, he hesitated to gamble his entire fortune on a visionary venture that might prove to be impracticable. As to the deficiency, he could get that as a loan or a gift from one or more of his many wealthy friends who had every confidence in him. Should the scheme fail, he would be penniless--possibly friendless. “Do you believe a flight to another planet and back could be made successfully in the _Sphere_ so equipped?” he asked. Robert considered carefully. He did, but the professor’s question renewed many doubts. Most of all, he hesitated to involve his would-be benefactor in a disastrous venture. “I do,” he answered truthfully, at last. “So do I,” supplemented the professor, stoutly, as if to help convince himself. “Would you be willing to undertake such a journey?” he asked suddenly, fixing his eyes keenly upon his host. “Yes, sir!” responded Robert quickly. His prompt reply and evident sincerity convinced Professor Palmer that he was in earnest. The professor had decided. Nothing risked, nothing gained. As for Robert, nine months of trench warfare in France had steeled him against fear of anything except women and the devil. “It is settled, then,” concluded the professor, unconsciously authoritative. “You will come to my home, and together we will supervise the completion of the _Sphere_.” “But the _Sphere_--,” began Robert, surprized by the professor’s quick decision. “We will have it conveyed to my estate, where the light and space will be much better; and where I can look after you better, my boy.” His face softened. Ah, an old bachelor had not all the advantages. What would he not give to have a son like this! Something about Robert’s hesitation reminded him abruptly of an important consideration. “I am forgetting,” he apologized. “Your interest must be fully protected. We will draw up a contract whereby full possession of the _Sphere_ and all its equipment, now and always, will remain yours. I will undertake to complete it, defraying all expenses, in return for which I ask the use of the _Sphere_ in a flight to Mars and back if possible.” “That is more than fair,” Robert replied, feeling ashamed of a shortlived, though natural, apprehension. 4 Robert found Professor Palmer’s homestead vastly more cheerful than his own gloomy quarters.