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Lecture: Reformations and Scientific Revolution (1500-1650)

The purpose of my lectures is not to list and explain pieces of engineering, but this one may look more like this than I intend! What we have in this era is a broadening of scientific knowledge going hand-in-hand with the development of instrumentation that could measure with greater accuracy and influence science even more. At the same time, theories were being proposed that shifted people's view of the universe. Science, technology, and even art seem more on the same wavelength in this era than ever before.

The context

The background to this era of technology consists of religious change and the political and social upheaval that followed.

The rise of Protestantism was strongly influenced by technology. During the Middle Ages and into the early Renaissance, the Roman Catholic Church had a monopoly on Christianity. The Church was a large political and economic structure as well as a religious institution. Much land throughout Europe was owned by the Church, and bishops were important political figures. The famines and Black Death of the early 14th century had weakened the Church due to their lack of response, as had the Avignon Papacy. This had begun in 1309, when the pope had decided that Rome had become too dangerous and moved the papal court to Avignon. By the time the papacy returned to Rome in 1377, Avignon had elected its own pope and there were two. There simply cannot be two popes - the pope is supposed to be the Vicar of Christ on Earth. The situation was not resolved until 1414.

pressThe result was the rise of mystical religion and commentaries on the Church, even as the Church itself became more worldly and corrupt in the 1500s. Popes defended their thrones militarily and wealthy Italian families conspired to win the papacy. Wealth came into the Church through new methods, such as the sale of indulgences, which forgave people for sin in return for money. Humanist scholars, particularly those in northern Europe at a distance from Rome, wrote open critiques of Church practices: ignorant clergy, wealthy popes and bishops, corruption. And these critiques could be printed on the new technology.

Prior to Gutenberg's movable type press, hand-written manuscripts and woodblock printing were the methods of distributing information on paper. Handwriting created unique works, and woodblocks gradually wore down. What Gutenberg, a metal-smith, created was movable type, each letter made of molten metal poured into a mold. One could produce many of these letters, then arrange them in frames for printing a page. When Martin Luther wrote his 95 Theses which started the Protestant Reformation, it was printed on a press and distributed. It was written because of Luther's disgust at the sale of indulgence papers, which were also printed on a press. The ideas of Protestantism spread because of the press. Protestants believed that the way to get closer to God, to assure oneself of God's grace, was to read the Bible. Luther himself had translated the original Greek Bible into German, and new editions in various languages were being printed.

Metals and Milling

We know quite a bit about metallurgy and milling technology during this time thanks to "Agricola", the pen-name of Georg Bauer, who published De re metillica in 1556. Agricola, for his part, borrowed a lot of material from Vanoccio Biringuccio, who had published De la pirotechnia in 1540, detailing many metallurgical processes. Mining was so important and made so much money, that water power was implemented early to pump water out of mines. To work metal successfully, a source of water was needed, not only for running waterwheels but to wash the product at various stages. Charcoal was also needed in great supply; since it was made from wood, a source of wood was important too, which helps explain the superiority of eastern European metallurgical practices. Charcoal imparted fewer impurities to metal than any other fuel.

Metals were smelted, heated to remove impurities and extract substances like bismuth and antimony sulfide, and different kinds of rocks were added to fuse rock away from the minerals. Copper was purified by removing sulfur and iron, in a series of complex processes. A process known as liquidation was developed to extract amounts of silver and gold from copper; it liquefied the copper and lead together, then cooling the copper so that the gold and silver stick to the lead. The lead was then treated by cupelling, using a blast of air to solidify the lead. The last step was to use nitric acid to remove the silver from the gold. Although cuppellation was an old process, there are no descriptions of liquidation till the 15th century. These techniques worked so well they didn't change much until the 19th century.

Copper was needed for decorative items and utensils, but its main application was in alloys, especially the making of bronze. Bronze (copper + tin) was strong and could be casted into shapes; it had been a popular medium for millennia, but making the process more efficient could produce more for less. Pewter, an alloy of tin and lead, was used to make cheaper plates and cups, and could be easily cast in iron molds. At first, printing letters were made of cast pewter, but if the pewter was too soft it would wear down. This need caused technicians to harden pewter with other substances (such as the bismuth they'd removed as an impurity). By the 17th century typeset was made of very hard lead alloys, and is still used on printing presses today.

blast furnaceIron was also subject to changes during this era. Because iron had been so common for so many centuries, it's actually harder to find primary sources about it than about more exotic "non-ferrous" metals. The innovation of the 15th century was the blast furnace, which replaced the slow, tedious method of reducing iron to wrought iron by removing as many impurities as possible. In the blast furnace, the iron remains in contact with the hot charcoal, which allows carbon to enter the iron, helping separate it from other impurities. The product could then be shaped by the hammers of a blacksmith. Viscous cast iron could be put in molds for casting cannon. Again the waterwheel helped, using the cam to push bellows and keep the furnaces hot.

The Cosmological Shift

In the 15th century, Polish priest Nicholas Copernicus developed an alternative to the cosmology of Ptolemy, which had been cemented by Aristotelian philosophy. The universal view that had held for centuries featured a motionless earth at the center, with planets and stars on spheres, arranged in concentric circles moving outward from the earth. This Ptolemaic-Aristotelian system had fit with the Catholic Church's interpretation of the Bible, which stated that the earth was still. But Copernicus was a mathematician, and he was bothered by the complexity of a system that had to add a sphere every time a new object was discovered in the sky or a planet exhibited retrograde motion. To simplify the system with hundreds of spheres, he put the sun at the center. Mathematically it made things simpler. Knowing the Church would object, Copernicus did not allow his On the Revolutions of the Heavenly Bodies to be published till after his death.

hydrostatic balanceIt had an influence, however, in its mathematical elegance, and could be used for calculations so long as everyone understood it was theoretical. Galileo's great achievement, or his great crime (depending on your point of view) was to use a telescope to actually look at the sky closely and see that Copernicus was correct. Telescopes at the time were primarily used for shipping, both on ships to see distances and on shore to see when ships were coming in with goods to trade. They had about 3X magnification. Galileo already had a history of working with mechanics to disprove Aristotle. He did experiments to show that light and heavier objects fell at the same rate, a direct contradiction of Aristotelian physics. Even though he was professor of mathematics at the University of Padua, he was fascinated by technology. He invented a pump and several types of balances or scales. In 1609 he developed a telescope with 20X magnification, and it was with this invention he saw mountains and bumps on the supposedly spherical planets, and moons orbiting around Jupiter.

Unable to consider what he saw as "theoretical", Galileo published his discoveries as fact. As a result, he was forced to recant them by the Catholic Church's investigative arm, the Inquisition. Found guilty of heresy, he spent the last years of his life under house arrest. But his work had influence beyond his circumstances, and the experimental method was a huge influence. During the same era, other experimentalists included Francis Bacon, who developed a philosophy based on empiricism, the use of the five senses to determine knowledge.

The Mechanical Arts

It is during this "Early Modern" era that "mechanical arts" come into their own intellectually.  The change of ideas was evident in Galileo's work, which leaned toward the experimental rather than philosophical. It was expanded by Bacon, and later solidified by Isaac Newton.

Boyle pumpContemporary with Isaac Newton were experimenters like Robert Boyle, who created the air pump. When air was pumped out of the device, it create a vacuum. Plants, insects, animals could be placed in the glass sphere, and the effects of a lack of air could be studied. This led to a better understanding of air and gasses. But what's interesting is that instead of starting with a theory and proceeding to build a device to prove the theory, Boyle began with the experiment itself. Although some historians of science see in this the evolution of the scientific method, I also see it as representing the new reliance on mechanics and empiricism as legitimate foundations of knowledge. It also killed quite a few little animals.


This division of science and technology is a tension throughout the class, and between historians of science and historians of technology. Among the practical inventions of this era were instruments designed for scientific experimentation, navigation, clockmaking, and cutting cylindrical forms. Brass (an alloy of copper and zinc, mixed with charcoal) could be used by skilled artisans to create sophisticated scientific instruments. At the end of the 16th century, medieval instruments such as astrolabes (which calculated the position of stars), quadrants, and sundials were declining in use. New techniques were developed to respond to the needs of an age of dividing up land as manorialism declined. By attaching part of an astrolabe to a tripod, and adding a compass, you can develop a surveying instrument. Navigational instruments were adapted - in the 1590s Captain John Davis adapted a cross-staff (used to measure the altitude of the sun to help find latitude) into a back-staff (which did the same with shadows, so you didn't have to stare into the sun).

Computers (instruments for making computations) were also adapted. Rulers (also called scales) were invented for various uses. Galileo himself used an improved version of a hinged and graduated ruler called the "sector", and found it so useful he hired a full-time instrument-maker, Marcantonio Mazzoleni, to produce it for commercial sale.


Mathematician John Napier discovered logarithms in 1614 as a means to simplify large calculations by using tables. Such tables could be carved onto portable "rules" for easy use. gunter scaleGunter's scale (invented 1620) used it to create a table for navigators, on a board a couple of feet long and about 1.5 inches wide. In 1622 William Oughtred made a sliding rule, so that the numbers being compared could by physically lined up with each other on the logarithmic scale.

Clock with pedestal (Pendule sur gaine), ca. 1690 Movement by Jacques III Thuret (French, 1669–1738) or more likely his father, Isaac II Thuret (French, 1630–1706); case by André-Charles Boulle (French, 1642–1732) after designs supplied by Jean Berain (French, 1640–1711).
The slide is just an example of the inventiveness of the era. In 1645, mathematician Blaise Pascal presented his "pascaline" (shown left), a calculating mechanism made of brass that could add and subtract. pascalineMap-makers were happy to purchase the new "hodometers", which used compasses and the measuring of mileage on cartwheels. Techniques for turning wood on a lathe developed in leaps and bounds, to help create wooden screws for presses and lathe machines themselves. Metal-cutting on a lathe developed as a separate technique - the 1550 Nuremberg printing press had copper screws,and later they were made of iron. Threaded screws were starting to be made at the beginning of the 17th century.

Glass became more important for scientific instrumentation. Obviously this was true for making lenses, both for telescopes and microscopes. And thermometers (yes, Galileo invented one of these too) were made of glass and used to measure body temperature for the first time. Galileo's student Torricelli invented the barometer in 1643. The glass-blowers' talents were needed to make these devices, and the center of glass methods was Venice, in particular the island of Murano, where glass-blowers were restricted to prevent fires in Venice proper and espionage. Murano's glass techniques were the envy of Europe, and Venice wanted them kept secret. But it was Ippolito Francini of Florence who modified the lathe so it could grind lenses more precisely. Galileo bought his glass for his telescopes. To create better telescopes, such achievements had to be combined with better mirrors and better sheet brass for the housings.

hairspringClocks, of course, are also instruments. Spring-driven clocks, which had been around since the 15th century, improved in the 17th. The springs were another product of the advancements in metallurgy, and were improved upon with the invention of the hair-spring by Christiaan Huygens (who likely had invented the pendulum clock awhile before) and Robert Hooke (an inventor of the microscope). The hair-spring (shown left) helped control the balance wheel and thus the movement of the clock's hands. It provided enough stability to enable to making of smaller timepieces. The pocket watch would be popular throughout the 18th and 19th century, as the pace of life quickened with industrialization. Larger clocks were works of art beginning in the 17th century. The one on the right featured an eight-day spring movement, and was made of oak, brass, pewter and bronze.

And in many ways, the spring-driven clock changed everything. Here's a brief video about how and why:

spring clock


It became obvious during this era that scientists, artisans and technicians were dependent on each other. But there is some question as to which of the many causes were actually causes, and which were effects. And what was the role of the Protestant Reformation, other than causing (or resulting from) a printing boom? Some historians believe that the questioning of the Catholic Church in general, once it broke away in the form of Protestantism, "freed" scientists to do what they needed to do without reference to Catholic dogma. What happened to Galileo supports this point of view. But I find it hard to swallow, since so many great ideas came from scholars who were Catholic. It makes me wonder whether English Protestants like Newton and Boyle have been given too much of the spotlight.