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The Invention of the Steam Engine : The Life of James Watt
Part 1: The early life of James Watt and his introduction to the Newcomen steam engine
James Watt's Sketch For His Early Steam Engine DesignExtracts from:
Capital and Steam Power 1750-1800
Written by John Lord of London
Capital and Labor - The Invention of the Steam Engine : James Watt's Early Inventions
 
The Life of James Watt
- Part I: The Early Life of James Watt and his introduction to the steam engine
- Part 2: James Watt partners with industrialist, Micheal Boulton
- Part 3: The Firm of Boulton & Watt
- Part 4: The Steam Engine Grows in Popularity
- Part 5: Conclusion
James Watt
Related Research Material
- Second biography of James Watt
- Pictures of James Watt's steam engine design
- History of Steam Engines
- Industrial Revolution

James Watt, the grandson of a teacher of mathematics, and the son of a shipwright merchant of Greenock, was born in 1736. On the advice of a Glasgow Professor, he was sent to London in 1755 to be apprenticed to a mathematical instrument maker. However, on arriving in London he discovered that the seven years' apprenticeship rule of the gild was largely insisted upon, and it was only with difficulty that he could find any one who would take him for so short a time as a year This was finally arranged, and a Mr. Morgan was to give him a year's instruction for twenty guineas.

His stay in London was characterized by great frugality and occasional fears of the press-gang In a letter to his father, he writes: " They now press anybody they can get, landsmen as well as seamen, except it be in the liberties of the city, where they are obliged to carry them before my Lord Mayor first; and, unless one be either a Prentice or a creditable tradesman, there is scarce any getting off again, and if I was carried before my Lord Mayor, I durst not avow that I wrought in the City, it being against their laws for any unfreeman to work, even as a journeyman, within the liberties."

When James Watt had completed his training, he returned to Glasgow to set up in business for himself, only to be met by the same restrictions that existed in London; the gilds were still struggling to retain their control of the trade of the chartered towns, and as Watt was neither the son of a burgess nor the husband of the daughter of one, and not having served a regular apprenticeship, he was refused permission to open his shop. Watt's early friendship with the Glasgow professors now stood him in good stead. He was made mathematical instrument maker to the University, and given a shop within its walls, where he carried on his trade. Even in this small venture Watt lacked capital, and took one John Craig into partnership, the details of which give an insight into the scale of a small business in 1750, and the relatively small part fixed capital played. The journal of the partnership begins with the following entry: " An Inventory of tools, goods, etc., belonging to us, James Watt and John Craig, each one-half. Taken October 7th, 1759, at Glasgow," and then enumerates a variety of mechanical tools from a turning lathe to a flatting mill, with philosophical instruments, chiefly mathematical and optical, the whole to the value of which £91 I9S. 3.5d., with cash on hand, £I08 8.5d., made the total capital £200.

During the period dealt with in the journal, 1759-1765, the ready money sales brought in about £50 per month, or £600 per annum, a large portion of which went to pay wages and buy materials. Watt, himself, is credited with a salary of £35 per annum, rather more than twice the wage of a potter, and rather less than twice that of a miner. From employing one journeyman and occasional extra help, the business expanded so that in 1764 Watt employed sixteen men of various capacities.

In 1763, James Watt left his rooms in the University, and in July of the following year married his cousin, Miss Miller. During this time, too, Watt made the acquaintance of Professors Black and Robison, of Glasgow University.

During his stay in the University, Watt looked after the mathematical instruments which belonged to it, and, " in the winter of 1763-4, having occasion to repair a model of Newcomen's engine, belonging to the Natural Philosophy class," his mind was again directed to the study of the steam engine.

He repaired it, but upon its being set to work, it was discovered that it would only go a few strokes at a time, though the boiler was big enough to keep it well supplied with steam. The large amount of water that it was necessary to inject to condense the steam, put Watt on the track of the theory of latent heat, which Dr. Black had already discovered.

Upon thinking the matter over, James Watt saw that there was a great wastage of steam and power through the alternate heating and cooling of the cylinder, and, upon reflecting further, he perceived " that in order to make the best use of steam, it was necessary first, that the cylinder should be maintained always as hot as the steam which entered it; and, secondly, that when the steam was condensed, the water of which it was composed, and the injection itself, should be cooled down to a 100 degrees, or lower where it was possible. The means of accomplishing these points did not immediately present themselves; but early in 1765 it occurred to me that if a communication were opened between a cylinder containing steam and another vessel, which was exhausted of air and other fluids, the steam, as an elastic fluid, would immediately rush into the empty vessel, and continue to do so until it had established an equilibrium; and if that vessel were kept very cool by an injection, or otherwise, more steam would continue to enter until the whole was condensed. But both the vessels being exhausted, or nearly so, how were the injection water, the air which would enter with it, and the condensed steam, to be got out?" This was eventually solved " by employing a pump or pumps to extract both the air and the water, which would be applicable in all places, and essential in those cases where there was no well or pit."

This is James Watt's great discovery the theory of separate condensation, it made the steam engine a useful and economical source of power, and was so successful, that for a hundred years after his invention no drastic alterations were made in the type of steam engines in common use. Following naturally from the main discovery were these corollaries. The piston in Newcomen's engine was kept air-tight by a supply of cold water on it upper surface- this was no longer possible, and Watt was forced to use " oils, wax, resinous bodies, fat of animals, quicksilver, and other metals in their fluid state."

Again, the cylinder being open, the air which entered to press down the piston in the old atmospheric engine would cool the cylinder. Therefore, he proposed to close the head of the cylinder, and to allow the piston rod to slide through a stuffing box, while the piston was to be forced down, not by the air, but by steam introduced above it.

The cylinder was cooled, too, by the open air on its side; this Watt remedied by enclosing the cylinder in a second case covered with wood, and filling the space between with steam. Thus, all Watt's improvements were economical of heat. Economy in heat meant economy in steam, and economy in steam meant economy in working costs, and, above all, in coal.

James Watt now spent all his spare time in reducing the theory of his improvement to practice; he carefully thought out all the details, and calculated the amount of steam required. But, before long, he felt the need of an experiment on a large scale.

That is the story of the inventor, but the invention was a long way from being a commercial proposition, and much money had to be spent, and much capital laid out before Watt was in a position to supply power to order.

James Watt himself had no money to spend on experiments, and no capital with which to start manufacturing steam engines, should his experiments prove successful. Therefore, he had to look elsewhere for his capital, and the two men who provided it, and made possible the successful development, were Roebuck and Boulton. Their story forms an important chapter in the history of capitalism, and in their careers can be seen most of the difficulties and opportunities that faced the men who became the leaders of the Industrial Revolution.

Next page > James Watt partners with Matthew Boulton

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