Science & Technology

Technology

he Renaissance had more obviously technological content than the Reformation. The concept of "renaissance" is elusive. Since the scholars of the Middle Ages had already achieved a very full recovery of the literary legacy of the ancient world, as a "rebirth" of knowledge the Renaissance marked rather a point of transition after which the posture of deference to the ancients began to be replaced by a consciously dynamic, progressive attitude. Even while they looked back to classical models, Renaissance men looked for ways of improving upon them. This attitude is outstandingly represented in the genius of Leónardo da Vinci. As an artist of original perception he was recognized by his contemporaries, but some of his most novel work is recorded in his notebooks and was virtually unknown in his own time. This included ingenious designs for submarines, airplanes, and helicopters and drawings of elaborate trains of gears and of the patterns of flow in liquids. The early 16th century was not yet ready for these novelties: they met no specific social need, and the resources necessary for their development were not available.

An often overlooked aspect of the Renaissance is the scientific revolution that accompanied it. As with the term Renaissance itself, the concept is complex, having to do with intellectual liberation from the ancient world. For centuries the authority of Aristotle in dynamics, of Ptolemy in astronomy, and of Galen in medicine had been taken for granted. Beginning in the 16th century their authority was challenged and overthrown, and scientists set out by observation and experiment to establish new explanatory models of the natural world. One distinctive characteristic of these models was that they were tentative, never receiving the authoritarian prestige long accorded to the ancient masters. Since this fundamental shift of emphasis, science has been committed to a progressive, forward-looking attitude and has come increasingly to seek practical applications for scientific research.

Technology performed a service for science in this revolution by providing it with instruments that greatly enhanced its powers. The use of the telescope by Galileo to observe the moons of Jupiter was a dramatic example of this service, but the telescope was only one of many tools and instruments that proved valuable in navigation, mapmaking, and laboratory experiments. More significant were the services of the new sciences to technology, and the most important of these was the theoretical preparation for the invention of the steam engine.

The steam engine

The researches of a number of scientists, especially those of Robert Boyle of England with atmospheric pressure, of Otto von Guericke of Germany with a vacuum, and of the French Huguenot Denis Papin with pressure vessels, helped to equip practical technologists with the theoretical basis of steam power. Distressingly little is known about the manner in which this knowledge was assimilated by pioneers such as Thomas Savery and Thomas Newcomen, but it is inconceivable that they could have been ignorant of it. Savery took out a patent for a "new Invention for Raiseing of Water and occasioning Motion to all Sorts of Mill Work by the Impellent Force of Fire" in 1698 (No. 356). His apparatus depended on the condensation of steam in a vessel, creating a partial vacuum into which water was forced by atmospheric pressure.

Credit for the first commercially successful steam engine, however, must go to Newcomen, who erected his first machine near Dudley Castle in Staffordshire in 1712. It operated by atmospheric pressure on the top face of a piston in a cylinder, in the lower part of which steam was condensed to create a partial vacuum. The piston was connected to one end of a rocking beam, the other end of which carried the pumping rod in the mine shaft. Newcomen was a tradesman in Dartmouth, Devon, and his engines were robust but unsophisticated. Their heavy fuel consumption made them uneconomical when used where coal was expensive, but in the British coalfields they performed an essential service by keeping deep mines clear of water and were extensively adopted for this purpose. In this way the early steam engines fulfilled one of the most pressing needs of British industry in the 18th century. Although waterpower and wind power remained the basic sources of power for industry, a new prime mover had thus appeared in the shape of the steam engine, with tremendous potential for further development as and when new applications could be found for it.