Smeaton, John (1724–1792)

Questions on this topic? Just ask!

John Smeaton was one of the first great British civil engineers, the first to use the title "Civil Engineer" (seeing himself as a professional ranking alongside doctors and lawyers), and the first to achieve distinction as an engineering scientist.

Smeaton was born on June, 8, 1724 at Austhorpe Lodge, near Leeds. He was the son of a successful Leeds lawyer, and from an early age Smeaton developed an interest in mechanics (which his father indulged by providing a workshop), building a working model of a steam engine being erected at a nearby colliery (coal mine). It was the desire of Smeaton's father that his son should succeed him, and at the age of sixteen Smeaton was employed in his father's office. In an attempt to wean him from his mechanical pursuits and partly to give him a good legal education, Smeaton was sent to London. In London, Smeaton's desire to pursue a mechanical career was not suppressed, and his father finally agreed to finance his training as a philosophical instrument maker, to make instruments or apparatus for study of natural philosophy or the physical sciences. The young Smeaton did not however, live the life of a workman, but attended meetings of the Royal Society and was often in the company of educated people. He was soon able to set up as a mathematical instrument maker (making instruments used by draftsmen, navigators, or land surveyors) in London, and at the age of twenty-six presented a paper before the Royal Society on improvements in the marine compass. More papers quickly followed, and in 1753 he was elected a fellow.

In 1759 Smeaton presented to the Royal Society a paper entitled "An Experimental Enquiry concerning the natural Power of Water and Wind to turn mills, and other machines, depending on a circular motion." This paper was the result of a series of experiments carried out in 1752 and 1753, Smeaton having delayed its publication until he had put his deductions into practice. At the time there was a lively debate as to the merits of undershot and overshot waterwheels, but little published data to substantiate various claims. Smeaton's solution to this problem depended solely on experiments made with working model waterwheels. He wanted to compare the "power" of the water delivered to the wheel with the useful "effect" produced by the wheel.

Smeaton's elegant experimental technique enabled him to deal with both hydraulic and mechanical friction losses, allowing him to calculate water velocity at the wheel and thereby determine an "effective" or "virtual" head. Smeaton's experimental apparatus was a brilliant device that enabled him to measure the efficiency of the waterwheel, alone rather than the overall efficiency of the experiment. Smeaton was able to conclusively show that a water-wheel when driven by the weight of water alone, is about twice as efficient as when driven by the impulse of water. This demonstration ensured that British mills, wherever possible, from then on would be fitted with overshot or breastshot waterwheels, rather than undershot.

Smeaton also turned his attention to windmills, but with inconclusive results. This may have been because there was no clear-cut issue to be resolved as was the case with the waterwheel regarding which form was the best type. However, he did produce useful guidelines on the construction of windmills. Smeaton was careful to distinguish the circumstances in which a model test rig differs from the full-size machine, cautioning, "otherwise a model is more apt to lead us from the truth than towards it." Smeaton's experiments demonstrated that work done by a prime mover was a good measure of its performance. In 1765, seeing a need for a practical measure, he fixed the power of a horse working an eight-hour day as 22,000/ft. lb/min.

Britain in the mid-eighteenth century experienced rapid expansion in the number and scale of public works. This enabled Smeaton, in 1753, to give up instrument-making and become a consulting civil engineer, building both wind and water mills, canals, bridges and, from 1756 to 1759, the Eddystone lighthouse. In preparing his designs, Smeaton adopted a scientific approach. It was his practice to prepare a report and have the work carried out by a resident engineer.

In 1766 Smeaton designed an atmospheric steam-pumping engine for the New River Company; however, when the engine was set to work, its performance was less than Smeaton had expected. Realizing his knowledge of steam engines was deficient, he approached the problem in the same manner as he did his study of water and wind power—by deciding to carry out a systematic, practical study. His first action was to have drawn up a list of all steam engines working in the district around Newcastle. Of these, fifteen were chosen and a set of engine tests made. Smeaton was the first to gather such comprehensive data, from which he calculated for each engine the "great product per minute" or power, and "effect per minute of one bushel of coal per hour" or performance.

Smeaton constructed on the grounds of his house, a small experimental atmospheric engine with a ten-inch cylinder. Beginning in 1770 he made some 130 tests over two years. All relevant measurements were made, including temperature, pressure—both internal and barometric, evaporation of water per bushel of coal, etc. Smeaton's method of testing was to adjust the engine to good performance and take measurements, then alter one of the parameters and take further measurements. By this means he was able to optimize valve timing, piston loading, and size of injector nozzle. He also carried out experiments to test the evaporative powers of various types of coal. From the knowledge gained, Smeaton drew up a table for the proportions of parts for Newcomen-type engines. Although Smeaton's experiments added nothing to the invention of the Newcomen engine, establishing proper proportions for engines enabled him to built more efficient and powerful engines. The great leap forward in the operation of atmospheric steam engines came with Watt's separate condenser.

Smeaton was a born mechanic and incessant experimentor, but a man of simple tastes and wants. He limited his professional engagements in order to devote a certain portion of his time to scientific investigations. One of Smeaton's rules was not to trust deductions drawn from theory when there was an opportunity for actual experiment. In 1771 Smeaton founded a club for engineers, which later came to be call the "Smeatonian Society."

In 1756 Smeaton married Ann Jenkinson, the daughter of a merchant tailor and freeman of the city of York. They had two daughters. Ann Smeaton fell ill and died in 1784. Smeaton continued working until 1791, when he retired to Austhorpe Lodge to prepare for publication descriptions of his various engineering works. While walking in his gardens he suffered a stroke and died six weeks later, on October 28, 1792, in his sixty-ninth year.

Newcomen, Thomas; Watt, James.

Farey, J. (1827). A Treatise on the Steam Engine. London: Longmans.

Ress, A. (1813). The Cyclopedia; or Universal Dictionary of Arts, Science and Literature. London: Longman.

Smeaton, J. (1759). "An Experimental Enquiry Concerning the Natural Power of Water and Wind to Turn Mills and Other Machinery, Depending on a Circular Motion." Philosophical Transactions of the Royal Society 51:100–174.

Smeaton, J. (1791). A Narrative of the Building and a Description of the Construction of the Eddystone Lighthouse. London.

Smeaton, J. (1797, 1812). Reports of the Late John Smeaton, FRS Made on Various Occasions in the Course of His Employment as a Civil Engineer, Vol. 1 (1797), Vol. 2–3 (1812). London: Longman, Hurst, Rees, Orme, and Brown.

Smiles, S. (1904). Lives of the Engineers. John Smeaton. London: John Murrey.

Wilson, P. N. (1955). "The Waterwheels of John Smeaton." Transactions of the Newcomen Society 30:25–43.

This is the complete article, containing 1,285 words (approx. 4 pages at 300 words per page).