James watt was a Scottish inventor who made tremendous improvements to the already existing steam engine. He was a sick child and youth but he brushed away his physical ailments to become the most important inventors in world history. The improvements that he made became fundamental to the changes that took place during the Industrial Revolution in England.
Early Beginnings
James Watt was of a humble lineage born in Greenock, Scotland on January 19, 1736. Greenock was a small fishing town which grew to become a busy town with a fleet of steamships during Watt's lifetime. His father was a shipwright, ship owner and contractor, and he also served as the town's chief baillie. His mother, Agnes Muirhead was from a distinguished family and well educated. Thomas Watt, his grandfather, was a well-known mathematician and teacher along with being a baillie to the Baron of Cartsburn.
Mechanical Mind
James Watt was an intelligent child but he used to often fall ill. Initially, he was taught at home by his mother. Later, he joined Greenock Grammar School but his ill health did not permit him to attend school regularly. So, once again his mother began teaching him. From the beginning, Watt showed a great interest towards mathematics. He also used to wander to his father's carpenter bench. Seeing the tools on his father's bench made him familiar with their use and this was where he learnt the basics of engineering and tool making from his father.
While he was still very young, Watt began solving geometrical problems on his own. He also started experimenting with his mother's tea kettle, trying to understand the nature of steam.
As he grew up, his skills in the field of mathematics developed further. In his spare time, he made sketches with pencil, carved or went to his father's work bench and worked at the bench with wood and metal. He made many original pieces of mechanism, and a few beautiful models. He liked to repair nautical instruments. Among other pieces of apparatus made by Watt was a very fine barrel organ. As he grew up, his interest towards reading increased. He read a lot and found something to interest him in each book.
Apprenticeships
When Watt was eighteen years of age, he was sent to Glasgow to stay with his mother's relatives, and to learn the trade of a mathematical instrument maker. In no time he learnt all he had to from the mechanic he was apprenticed to and even outgrew him in terms of knowledge. It was then that a friend and professor at the University of Glasgow, Doctor Dick advised that he should go to London. James Watt moved to London in June 1755. Here, he began working for John Morgan, in Cornhill, for twenty guineas a week. But only a year had gone by when he was compelled to return home due to serious illness.
When he had recovered from his illness, James Watt returned to Glasgow in 1756. However, as he had been unable to complete his apprenticeship, he was prohibited by the guilds, or trades unions, to open a mechanical repair shop in Glasgow. Though the town of Glasgow had no mathematical instrument maker yet he was unable to open his shop. It was during this time that Doctor Dick came to his aid, and employed him to repair the astronomical apparatus that had come to the University. Watt couldn't have asked for more. He remained at the university till 1760, when he was allowed to open a mechanic shop in the city. Watt even worked briefly as a civil engineer though he always remained interested in mechanics. In his spare time, he made musical instruments and even made improvements in the construction of organs.
In 1764, Watt married his cousin Margaret (Peggy) Miller. Together, they had five children. She, however, died during childbirth in 1772. Watt remarried in 1777 to Ann MacGregor. They had two children together. In 1832, Ann too passed away.
Newcomen Steam Engine
While working at the University of Glasgow, Watt befriended the professors there. It was through them in 1763 that he came to know about the Newcomen steam engine. The university had a model of the steam engine and it was given to Watt for repairs. The Newcomen steam engine was used for pumping water from mines. He then began experimenting with steam though he had never seen an operating steam engine.
While Watt was given the steam engine to repair, Doctor Robison, who was a student at the University, and had befriended James Watt, used to come to his shop often. It was Robison who introduced Watt to the concept of steam engine. It was he who further suggested that the steam engine could be used for pushing carriages. This idea made Watt think. He then made a miniature model using tin steam cylinders and pistons attached to it to drive wheels with the help of a system of gears. He had however abandoned his search on steam engines soon after. Now, while examining the Newcomen steam engine, Watt remembered his own experiments and once again his interest in understanding and making better models of steam engine was renewed. This time, with renewed interest, he began researching on the properties of steam.
When he conducted his experiments, at first he used apothecaries' trials and hollow canes for steam reservoirs and pipes. He later used a Papin's digester and also a common syringe. The latter combination he found suitable and made a non condensing engine. In this engine, he used steam at a pressure of 15 pounds per square inch. He worked the valve by hand, and soon he saw that an automatic valve gear was needed to make a working machine. He, however, did not succeed in his experiment. Watt then, first repaired the Newcomen model of the steam engine, though it still did not work properly, and then continued with his experiments. While repairing the model, Watt saw that the boiler of the steam engine was made to scale but even then the boiler was incapable of furnishing enough steam to power the engine.
Problem With the Newcomen Model
Watt realized that about three-quarters of the heat of the steam was wasted as it was used in heating the engine cylinder on every cycle. Also, cold water was injected into the cylinder in order to reduce the pressure of the steam through condensation. The engine therefore wasted the energy in repeatedly keeping the cylinder heated. As a result less mechanical force was being produced. He saw that these were the flaws with the Newcomen model of the steam engine.
James Watt then began conducting experiments to improve the boiler. For his experiments, he constructed a new boiler where he could measure the amount of water evaporated and the steam condensed at each stroke of the engine.
James Watt Rediscovers Latent Heat
While conducting his experiments, Watt discovered that it required a very small amount of steam to heat a large quantity of water. He immediately began determining with precision the relative weights of steam and water in the steam cylinder when the process of condensation took place at the down stroke of the engine. It was then that Watt was able to independently prove the existence of "latent heat", which had already been discovered by scientist, Joseph Black, who was also a friend of Watt. With his new research, Watt went to Black who in turn helped Watt better understand the workings of latent heat. Watt was now certain that at the boiling point, the condensing steam was capable of heating six times its weight of water which was used for the process of condensation and thus the mechanical energy was getting wasted.
Watt Improvises With a Separate Condenser
Watt saw the importance of taking greater care to economize steam than had previously been attempted. At first, he economized in the boiler, and made boilers with wooden "shells" in order to prevent any losses by conduction and radiation, and used a larger number of flues to secure more absorption of the heat from the furnace gases. He also covered his steam pipes with nonconducting materials, and took every precaution to secure the complete utilization of the heat during combustion. He soon discovered that the action of the steam in the cylinder was responsible for the loss of heat.
After his scientific investigations, James Watt worked on improving the steam engine with an intelligent understanding of its existing defects, and with knowledge of its cause. Watt soon saw that in order to reduce the losses in the working of the steam in the steam cylinder, it was necessary to find a way to keep the cylinder always as hot as the steam that entered it.
James Watt Writes
James Watt wrote: "I had gone to take a walk on a fine Sabbath afternoon. I had entered the Green by the gate at the foot of Charlotte street, and had passed the old washing house. I was thinking upon the engine at the time, and had gone as far as the herd's house, when the idea came into my mind that, as steam was an elastic body, it would rush into a vacuum, and, if a communication were made between the cylinder and an exhausted vessel, it would rush into it, and might be there condensed without cooling the cylinder. I then saw that I must get rid of the condensed steam and injection water if I used a jet, as in Newcomen's engine. Two ways of doing this occurred to me: First, the water might be run off by a descending pipe... The second was, to make the pump large enough to extract both water and air. I had not walked farther than the Golf house, when the whole thing was arranged in my mind.”
The Solution
Then, in May 1765, Watt thought of a way to produce more mechanical power. The solution to the problem was simply to have a separate chamber apart from the piston to condense the steam while maintaining the temperature of the cylinder at the same temperature as the injected steam. This was done by surrounding the cylinder with a steam jacket. This meant that very little heat was absorbed into the cylinder during each cycle and more heat was generated to perform work. Based on this concept Watt did not take long to develop his model of the steam engine.
James Watt had invented his all-important separate condenser. He began constructing a smaller version of his steam engine with a separate condenser. He then proceeded to make an experimental test of his new invention. After a lot of effort and hard work, he managed to make his model. It was a crude model and did not work as efficiently as expected but it did produce more mechanical power. Encouraged by his experiment, Watt started to improve his model. Soon, he began the construction of a larger model based on his steam engine. Having taken this first step and making such a radical improvement, the success of this invention was followed by more acclaim.
After James Watt had built his larger experimental engine, he hired a room in an old deserted pottery. There he worked with mechanic Folm GardΓner. During this time, Watt met Doctor John Roebuck, a wealthy physician, one of the founders of Carron Iron Works. Now, Watt had a workable design of the steam engine but he lacked finances. Black had been providing Watt with money but it wasn't enough. So, John Roebuck gave the necessary money required to Watt though a large part of it was invested in getting the patent for Watt's invention. Due to lack of funds Watt was forced to work as a civil engineer for eight years.
In 1768, James Wattmet Matthew Boulton, whilehe was heading to London to get his patent. Matthew Boulton wanted to buy an interest in the patent. With Roebuck's consent, Watt offered Matthew Boulton a one third interest. Subsequently, Roebuck proposed to transfer to Matthew Boulton, one half of his proprietorship in Watt's inventions, for a sum of one thousand pounds. Sometime later, when Roebuck became bankrupt, it was Matthew Boulton, who came to help Watt. The partnership between Watt and Boulton was successful and lasted for twenty five years.
First Engines
In 1776, the engines designed by Watt were being installed in many commercial enterprises. They were used to power pumps and produced only reciprocating motion to move the pump rods at the bottom of the shaft. The next five years, Watt continued to install the steam engines. Now that the steam engine was hugely successful, Boulton urged Watt to innovate further so that the steam engine could be used for grinding, weaving and milling.
For the next few years, Watt continued to improve and modify his design of the steam engine. Among the improvements was the use of the steam indicator which told about the pressure of the steam inside the cylinder against its volume. Watt kept this as his trade secret. Another important invention, about which Watt was immensely proud, was the creation of parallel motion required in double-acting engines as it produced the straight line motion required for the cylinder rod and pump, from the connected rocking beam, whose end moved in a circular arc. This improvement was patented in 1784. These improvements made the steam engine designed by Watt five times more fuel efficient than the Newcomen Model.
Later Years
Watt's steam engine was a great success. He, however, did not stop there and continued to invent. Among his other notable inventions was the copying machine. It was in 1780 that he had the patent for the copying machine.
Together, Watt and Boulton started the Soho Manufactory to manufacture their engines. The manufactory opened in 1796. In 180os Watt retired. By now, Watt's sons, Gregory and James Jr, were managing the enterprise. Even after his retirement, Watt continued to invent in his workshop at his home in Handsworth Heath, Staffordshire. His interest in civil engineering remained and he was often consulted on various projects. He later died on August 25, 1819 at the age of 83.