Historic Inventions

by Rupert Sargent Holland

The morning following that Sunday afternoon on which the idea of the condenser had occurred to Watt he borrowed a brass syringe from a college friend, and using this as a cylinder and a tin can as a condenser tried his experiment. The scheme worked, albeit in a primitive way, and Watt saw that he was on the track of an engine that would revolutionize the labor of men. But he saw also that it would take both time and money to bring his invention to its most efficient form.

His instrument-making business had prospered, he had taken in a partner, and the firm now employed sixteen workmen. About the same time he married, and rented a house outside the university grounds. Soon he was busily at work building a working model of his steam-engine.

A working model was very hard to make. Watt himself was a skilful mechanician, but the men who helped him were not. The making of the cylinder and the piston gave him the chief trouble. The cylinder would leak. It took him months to devise the tools that would enable him to make a perfect-fitting cylinder, and when he had accomplished that he still found that in one way or another a certain amount of steam would escape. Yet, although imperfect, his model was already many times more powerful than the Newcomen engine he had started with.

But before very long Watt found that this work was leading him into debt. He told his good friend Professor Black, who had discovered the latent heat of steam before Watt had, that he needed a partner to help him in his business of building engines. Black suggested Dr. Roebuck, who had opened the well-known Carron Iron Works near Glasgow. The two men met, and, after some negotiations, formed a partnership. Roebuck agreed to pay Watt’s debts to the sum of a thousand pounds, to provide the money for further experiments, and to obtain a patent for the steam-engine. In return for this he was to become the owner of a two-third interest in the invention.

It was more difficult to secure a patent in those days than in later times, for both the courts and the public considered that the right to make use of any new invention should belong to the whole world, and not alone to one man or to a few men. Watt’s models had to be very carefully made, and his designs very accurately drawn if he was to secure any real protection, and the preparation of these took a vast amount of time. But Roebuck continued to encourage him, and on January 5, 1769, he was granted his first patent, the very same day on which another great English inventor, Arkwright, obtained a patent for his spinning-frame. This first patent covered Watt’s invention of the condenser, but not his next invention, which was the double-acting engine, or in other words, a method by which the steam should do work on the downward as well as on the upward stroke.

With his patent secured Watt spent six months building a huge new engine, which he had ready for use in September, 1769. In spite of all his painstaking it was only a partial success. The cylinder had been badly cast, the pipe-condenser did not work properly, and there was still the old leakage of steam at the piston. Men began to doubt whether the new engine could ever be made to accomplish what Watt claimed for it, but although he realized the difficulties the inventor would not allow himself to doubt. Unfortunately his way was no longer clear. Dr. Roebuck met with reverses and had to end the partnership agreement, and Watt had to borrow money from his old friend Professor Black to secure his patent. To add to his distress his wife, who had been his best counselor, died.

Dr. Roebuck had owed money to a celebrated merchant of Birmingham named Matthew Boulton. Boulton had heard a great deal about Watt’s engine, and now consented to take Roebuck’s interest in Watt’s invention in payment of the debt. At the same time the firm of Boulton and Watt was formed, and in May, 1774, Watt shipped his trial engine south, and set out himself for Birmingham.

Boulton was a business genius, and Watt now found that he could leave financial matters entirely to his care, and busy himself solely with his engine. He had better workmen, better appliances, and better material in Birmingham than he had had in Glasgow, and the engine was soon beginning to justify his hopes. But the original patent had only been granted for fourteen years, and six of these had already passed. Boulton was not willing to put money into the building of a great factory until he was sure that the engines would be secured to the firm. Therefore more time had to be spent in obtaining an extension of the patent. This was finally done, and Watt was granted a term of twenty-four years. At once Boulton set to work, the first engine factory rose, and hundreds of men in England turned to Birmingham to see how much truth there was in the wonderful stories that had been spread abroad of the new invention.

Men soon learned that the stories were true. Orders began to flow in, and Watt had his hands full in traveling about the country superintending the erection of his steam-engines. The mines of Cornwall had become unworkable, and as a great deal depended on the success of the engine in such work, he traveled to Cornwall to make sure that there should be no faults. The miners, the engineers, and the owners had gathered to see the new engine. It stood the test splendidly, making eleven eight-foot strokes per minute, which broke the record. After that the other mines of Great Britain discarded the old expensive Newcomen engine, and sent in orders for Watt’s. The firm prospered, and the inventor began to feel some of the material comforts of success. He had married a second time, and made a home for his wife and children in Birmingham. Now, when he could spare the time from superintending the workmen and traveling over the country, he gave his thoughts to further inventive schemes.

Watt had not only invented the condenser and the double-acting engine, he had produced an indicator for measuring the pressure of steam in the cylinder, and also what was called the fly-ball governor, which took the place of the throttle-valve he had first used to regulate the speed of his engines. These improvements had so increased the uses of the engine that scores of rival inventors were abroad, and therefore he decided to secure a second patent. This he did in 1781, the patent being issued “for certain new methods of producing a continued rotative motion around an axis or centre, and thereby to give motion to the wheels of mills or other machines.” The next year he secured still another patent, and now he had so perfected his double-acting engine that it had a regular and easily controlled motion, in consequence of which, as he said in his specifications, “in most of our great manufactories these engines now supply the place of water, wind and horse mills, and instead of carrying the work to the power, the prime agent is placed wherever it is most convenient to the manufacturer.” This meant that the steam-engine had now reached the point where it could be made to serve for almost any purpose and placed in almost any position that might be required.