James Watt was born at Greenock, January 19, 1736. He was the fourth child in a family which, for a hundred years, had more or less professed mathematics and navigation. His constitution was delicate, and his mental powers were precocious. He was distinguished from an early age by his candor and truthfulness; and his father, to ascertain the cause of any of his boyish quarrels, used to say, "Let James speak; from him I always hear the truth." James also showed his constructive tastes equally early, experimenting on his playthings with a set of small carpenter's tools, which his father had given him. At six he was still at home. "Mr. Watt," said a friend to the father, "you ought to send that boy to school, and not let him trifle away his time at home." "Look what he is doing before you condemn him," was the reply. The visitor then observed the child had drawn mathematical lines and figures on the hearth, and was engaged in a process of calculation. On putting questions to him, he was astonished at his quickness and simplicity. "Forgive me," said he, "this child's education has not been neglected; this is no common child." [Illustration: Watt discovering the Condensation of Steam.] Watt's cousin, Mrs. Marian Campbell, describes his inventive capacity as a story-teller, and details an incident of his occupying himself with the steam of a tea-kettle, and by means of a cup and a spoon making an early experiment in the condensation of steam. To this incident she probably attached more importance than was its due, from reverting to it when illustrated by her after-recollections. Out of this story, reliable or not in the sense ascribed to it, M. Arago obtained an oratorical point for an _éloge_, which he delivered to the French Institute. Watt may or may not have been occupied as a boy with the study of the condensation of steam while he was playing with the kettle. The story suggests a possibility, nothing more; though it has been made the foundation of a grave announcement, the subject of a pretty picture, and will ever remain a basis for suggestive speculation. Watt was sent to a commercial school, where he was provided with a fair outfit of Latin and with some elements of Greek; but mathematics he studied with greater zest, and with proportionate success. By the time he was fifteen, he had read twice, with grave attention, Gravesande's "Elements of Natural Philosophy;" and "while under his father's roof he went on with various chemical experiments, repeating them again and again, until satisfied of their accuracy from his own observations." He even made himself a small electrical machine, about 1750-53; no mean performance at that date, since, according to Priestley's "History of Electricity," the Leyden phial itself was not invented until the years 1745-46.