taste for designing and engraving, as well as for mechanical invention. Among other contrivances upon which he exercised his ingenuity, was one for solving the famous problem of the Perpetual Motion; a chimera upon which young men of a turn of mind similar to his often try their untaught powers. One evening, we are informed, the young speculator was so sure that he had at length found out the Perpetual Motion, that he set out with the secret in his head to Woburn, intending to communicate it to a friend and old schoolfellow, Loammi Baldwin, in whose knowledge in such matters he placed great confidence. Loammi spent the night discussing the project with him, and so sensibly, that we are told young Thompson became convinced of the mechanical impossibility of his or any other Perpetual Motion, and returned to his counting-house in Salem next morning, resolved to attempt something less magnificent and more practicable.
About this time the differences between the mother country and the American colonies were beginning to assume a serious aspect. The imposition of the famous stamp tax in 1765 had excited great indignation among the colonists, and its repeal in the following year was celebrated with proportionate rejoicings. At Salem, where the commercial interest predominated, it was determined that there should be a great display of fireworks on the occasion; and as the town did not possess a professional pyrotechnist, Mr. Appleby's clerk contrived to get his services in that capacity accepted. Unluckily, while preparing some detonating mixture, he handled the pestle so as to cause an explosion, by which he was so severely burnt that his life was despaired of. At length he was able to remove from his mother's house at Woburn, to which he had been carried after the accident, and resume his employment at Salem. The renewed attempts of the mother country, however, to impose taxes on the colonies, followed as they were by the resolution of the merchants in the colonies not to import any of the products of the mother country, produced such a stagnation of trade in Salem, as at other towns, that Mr. Appleby, having no occasion for the further services of a clerk, was glad to give young Thompson up his indentures, and allow him to return to Woburn.
This happened apparently in 1767 or 1768; and for a year or two afterwards, Thompson's course of life seems to have been wavering and undecided. In the winter of 1769 he taught a school at Wilmington; and some time in the same year he seems to have thoughts of pursuing the medical profession, for which purpose he placed himself under Dr. Hay, a physician in Woburn, and entered zealously upon the study of anatomy and physiology. While with Dr. Hay, he is said to have exhibited greater fondness for the mechanical than for other parts of the profession, and to have amused himself by making surgical instruments. How long Thompson pursued his medical studies is uncertain; in 1770, however, we find him resuming his mercantile avocations, in the capacity of a clerk in a dry-goods store at Boston, kept by a Mr. Capen. He was in Boston during the famous riots which took place on the attempt to land a cargo of tea from a British vessel contrary to the resolution of the colonists against admitting British goods. Mr. Capen's business seems to have declined in the critical circumstances of the colony, as Mr. Appleby's had formerly done; and Thompson was again obliged to return to Woburn. During the summer of 1770, he attended, in company with his friend Baldwin, a course of lectures on experimental philosophy delivered in Harvard College; and at
