The local jealousy towards Watt had evidently been overcome, for in 1760 he was allowed to remove to larger and more central premises in the Saltmarket, nearly opposite St. Andrew’s Street. These he opened in partnership with Mr. John Craig, who supplied the capital required, and attended to the books. The new firm succeeded so well that a few years later, 1st December, 1763, the following advertisement appeared in the Glasgow journal: “James Watt has removed his shop from the Saltmercat to Mr. Buchanan’s land in the Trongate, where he sells all sorts of mathematical and musical instruments, with variety of toys and other goods.” At this time he also took a small mansion in Delftfield Lane (changed to James Watt Street), and was united in matrimony to his cousin, Margaret Miller.

The Æolipile.

He had also invented several new instruments, and improved others that had been in use before. His attention had ere this been directed to the steam-engine. It is known that Hero, a physician of Alexandria, who flourished A.D. 200, described an ingenious toy, of which steam was the motive power. It consisted of a hollow globe of metal, movable upon its axis. Beneath this, and communicating with it, was a small cauldron of water. The globe, which was often in the shape of a man’s head, was provided with a tube, opening at the side where the mouth was. When a fire was lighted under the cauldron, and the steam raised, it filled the globe, and then projecting itself against the air through the opening, the reactive force caused it to spin round upon its axis, as if it were animated by a spirit within. This was named the Æolipile.

Hero’s book lay buried in libraries until the revival of learning in the 16th century. The attention of many was then directed to the subject of steam as a motive power. In 1663, the ingenious Marquis of Worcester, one of the most wonderful men of modern times, published his “Century of the Names and Scantlings of Inventions.” He there describes “an admirable and most forcible way to drive up water by fire.” As his machine was actually used to elevate water at Vauxhall, he is entitled to the honour of being the first to bring the steam engine into use for practical purposes. In the “Scantlings” he also speaks of “a vessel to work itself against wind and tide, yea, both without the help of man or beast.” This is the first prophecy of the modern steamboat. The marquis fell into debt and disrepute, and n is never able to carry out all his bright designs. He was known to be a Papist, and suspected to be a madman. His difficulties and embarrassments increased from day to day: projects met with contumely and contempt. None valued them because none understood them. He lost his estate, lost his money, spent 13 years of his life in prison, and died a broken, disappointed man in April, 1667. His widow, the marchioness, did her best to turn his inventions to account, but with as little success as her lord, and so “the water commanding engine” dropped out of sight, and in the course of a few years was almost forgotten.

The next prominent experimenter on the powers of steam