With great difficulty he had persuaded two other men to join him. One furnished the scanty capital of _forty dollars_; the other gave the use of his machine shop, workmen and tools. Day and night he had worked to produce a SEWING MACHINE, sleeping but three or four hours out of the twenty-four, and eating, generally, but once a day, as he knew the machine must be built for forty dollars or not be built at all. The hour of trial had come that very day. The machine had been completed and put together, and _did not work_! One by one the workmen left him in disgust, but still the inventor clung tenaciously to his purpose, and refused to yield to defeat. All were gone but this companion, who held the lamp while the inventor worked. Loss of sleep, insufficient food, and incessant work and anxiety made him weak and nervous, and he could not get tight stitches. Sick at heart, the task was abandoned at last, and at midnight the worn and wearied men turned their backs upon their golden dreams and started for their lodgings. On their way they sat down upon the pile of boards, and were gloomily discussing the sad fate of the project, when his companion mentioned to the inventor that “the loose loops of thread were all upon the upper side of the cloth.” Instantly it flashed upon the inventor what the trouble was, and back through the night the men trudged to the shop, re-lighted the lamp, tightened a little tension screw, and in a few minutes ISAAC MERRITT SINGER had produced the first Sewing Machine that ever was practically successful. [Illustration: THE CRITICAL MOMENT. ]