But he was not alone in his sleeplessness. Robert slept not a minute that night. Over and over he reflected on just how he would best explain the intricacies of the _Sphere_ in order that he could convince Professor Palmer of its practicability. The fact that he lacked the necessary funds to complete the apparatus gave him considerable concern. For much, therefore, depended upon his ability to convince the professor of the feasibility of mere theories. 3 It was with considerable relief and expectancy on both sides that Robert and Professor Palmer shook hands in the big, high-ceilinged parlor of the old Sprague manor. Their footsteps echoed eerily through the house as they tramped back through the long dark hallway to a big barnlike addition which had long served as a workshop. Here Robert’s father had spent countless weary hours, to the despair of his good wife, who had already followed him to his reward. As they entered the doorway the professor became aware of an immense gray-black sphere in the dusk of the far end of the shop. The top of this sphere reached within a few inches of the lofty ceiling. It was probably twenty-five feet in diameter, and rested upon a short scaffold. What appeared to be curious round windows in its side, like portholes in a ship’s hull, gave it the appearance of a gigantic diver’s helmet. Robert approached the _Sphere_. Without hesitancy he selected and pressed upon what appeared to be an ordinary rivet-head like hundreds of others over the _Sphere’s_ shell. A round hatch, large enough to admit a man, swung open, disclosing a black and uninviting interior. Flustered, he courteously invited Professor Palmer to enter first. For an instant the professor hesitated. The weirdness of the whole affair suddenly struck him forcibly. This young man’s queer claims, the big manor with its eery echoes and atmosphere of dismal loneliness--all seemed to cry out to him to beware. The dull gray shape looming above them in the gathering twilight looked disquietingly like some freak prison, such as a madman might invent. Robert, sensing the professor’s misgivings, apologized for not having considered his difficulty in negotiating the unfamiliar interior in the darkness, and relieved him by entering first. A sharp click, and a comfortable glow of light suffused the interior. They passed up a brief, winding stairway into a long chamber. “This is the gyrostatic control which neutralizes the force of gravity,” Robert began, calmly, as if this assertion were the simplest thing in the world. He indicated a complicated mass of glittering machinery in the center of the compartment in which they stood. He reached for a small lever, and pulled it toward him. Simultaneously there was a soft whirring sound. For a moment the floor tilted slightly, then steadied again. “And the power for this?” queried the professor. “Furnished by storage batteries,” Robert explained. “The batteries are recharged by petrol-driven dynamos.”