by Dale Baker
Several Renaissance artist-engineers are credited with the development of perspective and technical drawing techniques. Filippo Brunelleschi (1377–1446) was a prominent architect of the Renaissance; he designed and supervised the construction of the dome of the Cathedral of Florence. He is credited with developing a geometrical understanding of perspective in about 1420; his understanding of perspective was rapidly adopted by Renaissance artists. He also invented several construction machines to help in the ambitious building construction projects that he supervised.
Mariano di Iacopo (1382–about 1458), known as Taccola (the crow), created two books of drawings of mechanical devices. He invented primitive forms of the cutaway and exploded views. In a cutaway view, portions of an object that block the view of the region of interest are cut away or removed so that the region of interest can be seen. In an exploded view, the components of an assembly are drawn separated from each other so that each component and its relationship with the others can be seen.
Leonardo da Vinci (1452–1519) is the best-known of these Renaissance artist-engineers. He used drawing and text together to perform thought experiments in many areas of engineering and science. These thought experiments include the design of a helicopter-like flying machine, a military tank, and a bridge. da Vinci developed the form of an engineering or scientific notebook that is used to support the process of engineering design or scientific inquiry. Figure 10 shows the design of a giant crossbow that da Vinci created.
Figure 6.10
Drawing of the design of a giant crossbow created by Leonardo da Vinci.
The Industrial Revolution
The Industrial Revolution occupied the eighteenth and nineteenth centuries. It was a time of sweeping technological changes, most of them developed by engineers. A primary aspect of the Industrial Revolution is that machine power replaced human and animal power. For example, steam engines were developed to pump water from mines, replacing human or animal powered pumps. Also, during the Industrial Revolution, the field of engineering continued a transition from application of rules of thumb to application of the growing body of knowledge of science and math. During the Industrial Revolution, familiar engineering disciplines (particularly civil engineering and mechanical engineering) began to emerge as identifiable specializations.
There were many technical advances made during the Industrial Revolution. We briefly consider five advances in this section: the developments of an accurate clock to measure longitude, steam engines, automatic machinery for creating textiles, mechanical printing, and steam-powered transportation. While there were many other technological advances during the Industrial Revolution, these give an overview of the different processes and technologies that became important in this era.
Measuring Longitude
Longitude is the distance east or west of the prime meridian, an imaginary north-south line that passes through Greenwich, England. It is measured in degrees, with positive longitudes being east of the prime meridian and negative longitudes being west of the prime meridian. The measurement of longitude (along with the measurement of latitude) is an essential component of navigation. It was especially important in the 1700s as Europeans explored the rest of the world and attempted to make accurate maps and charts. It was also important for ships returning from long voyages; if a ship’s captain did not correctly know the ship’s position, the ship could be run aground on reefs or rocks; many shipwrecks occurred for this very reason.
Correctly determining longitude was a very difficult problem given the technological capabilities of the early 1700s. It was considered to be so difficult but so important that in 1714, the British Parliament passed legislation that created the Board of Longitude. The Board of Longitude offered a prize of 20,000 pounds sterling (a significant fortune at the time) to anyone who could develop an accurate method of determining longitude.
The simplest method of determining longitude is to determine the difference between the time at one’s current location and the time at a known location (typically the prime meridian at Greenwich, England). In order to know the time at Greenwich, one must have a very accurate clock that has been set to Greenwich’s time. Then, as one travels, the clock always tells the time at Greenwich. So one approach, and the one that was ultimately successful at winning the longitude prize, is to develop an extremely accurate clock.
John Harrison (1693–1776) was an English clockmaker, who in a series of five designs developed a clock accurate enough to win the Longitude Prize (although the full amount of the prize was actually never awarded to him). His clock had to maintain accurate time on long sea voyages on which temperature, atmospheric pressure, and humidity varied dramatically. He developed several different ingenious mechanisms as part of the clock. One was called a grasshopper escapement. The escapement is the mechanism that converts the swing of the pendulum into the turning of a gear by a specific amount for each swing; the gear in turn drives the mechanism that moves the clock hands. Another mechanism invented by Harrison was a gridiron pendulum; this was designed so that the length of the pendulum did not change as the metal rods from which the pendulum are made expand or contract due to changes in temperature.
John Harrison’s development of his navel chronometer was motivated by the Longitude Prize. Because his early designs showed promise, he received funding from a clockmaker and from the Board of Longitude to further develop them. He never received the full amount of the prize. On several voyages, his timepieces kept time accurately enough, but the Board of Longitude had concerns that the accuracy demonstrated by his chronometers was due to luck and was not repeatable. Figure 11 shows the last of the chronometers that Harrison developed.
The development of the maritime chronometer by John Harrison is an example of a single individual, working more or less independently, who was able to develop the technology necessary to solve a significant societal problem. Even though his technical accomplishments were primarily made as an individual, his work was significantly influenced by the society in which he lived. His inventions went on to dramatically affect the future of maritime navigation.
Figure 6.11
H5, the last in a series of maritime chronometers invented by John Harrison to measure time accurately enough to compute longitude.
Substantial prizes to motivate progress on a technological problem have been offered often in the recent past. In the early 1900s, the Daily Mail newspaper announced and awarded many prizes for first events in aviation; these included the first flight across the English Channel in 1909 and the first flight across the Atlantic Ocean in 1919. The Ansari X Prize offered $10 million for the first nongovernment organization to launch a manned spacecraft into space; this prize was won on October 4, 2004, by SpaceShipOne. Since then, the X Prize Foundation has created several other prizes for genomics, automotive, and space accomplishments; these have yet to be won. The Defense Advanced Research Projects Agency (DARPA) created the grand challenge in 2004, in which vehicles without human drivers are required to navigate increasingly more difficult courses; winning teams in 2005 and 2007 have each received prizes of $2 million.
Steam Engines
One of the major technological changes that began during the Industrial Revolution was replacing water, wind, human, and animal power by machine power. This first occurred in the development of the steam engine. The steam engine was originally developed to pump water out of coal and metal mines. (Water collected in mines when they were sunk below the water table of the surrounding rock.) Mechanical pumping of water could remove much more water from a mine than humans or animals powering the pump. This allowed mines to be made deeper. Steam engines were also used to provide power for textile mills and other factories; this allowed mills to be located more conveniently to sources of raw materials and labor, rather than being located by streams and rivers.
The first commercially successful steam engine was developed by Thomas Newcomen (1664–1729) in England. His engine had a large cylinder in which a piston moved u
p and down. Steam was introduced into the cylinder and created a partial vacuum as it condensed; atmospheric pressure on the other side of the piston caused the piston to move. The piston was connected to a rocker arm; the movement of the rocker arm could be used to drive the pump. Figure 12 shows a cutaway drawing of the engine.
Newcomen and his partner John Calley had to reach an agreement with Thomas Savery (about 1650–1715), who had previously patented almost every imaginable use of steam power, before being able to commercially market their invention. The first Newcomen engine was installed in 1712. By the time the patent under which the machines were manufactured expired in 1733, about 100 of his steam engines had been built and installed. During this time, his design was improved so that it would run automatically. His design was very inefficient and required a large amount of fuel; it also had a limited height to which it could pump water. In spite of these drawbacks, it was widely adopted even after improved steam engines became available because of its mechanical simplicity.
Figure 6.12
A drawing of the Newcomen steam engine. The letter D marks the piston that moves up and down in the cylinder.
James Watt (1736–1819) developed an improved version of the steam engine. His engine was much more efficient than Newcomen’s, requiring only a quarter as much fuel, and thus was much less costly to run. He developed a working model of the engine in 1765, but required significant additional time to make the engine commercially successful. He received a patent on the engine design. He partnered with Michael Boulton (1728–1809), the owner of a successful iron factory, who provided the financial backing necessary to develop and market his engine. His first commercial engine was installed in 1776. In 1781, he developed a version of the engine that provided rotating motion (rather than the rocking motion of his previous engine) that could drive factory machinery. Watt eventually became a very wealthy man on the basis of sales of his steam engine.
The development of the steam engine was pivotal in several different areas. One was the introduction of machines into manufacturing of textiles and other goods. In addition, the steam engine transformed transportation; in particular, the development of the steamship and the steam locomotive greatly increased the speed with which people could move and increase the amount of materials and goods that could be moved. The metric unit of power is named after Watt. Thus, one can talk about a “100 watt” lightbulb as a bulb that uses 100 watts of (electric) power.
Textiles
One industry that was transformed by the Industrial Revolution was the creation of textiles (cloth). Before the Industrial Revolution, textile manufacture was a cottage industry; cloth was made by people working in their homes or in small groups. After the Industrial Revolution, cloth was made in large factories using machinery powered by water or steam engines.
The creation of textiles involves two processes. The first, spinning, is the manufacturing of thread or yarn from fibers such as cotton or wool. The second is weaving the thread or yarn into fabric. Inventions in the textile industry occurred both in England and the United States.
The first cotton mill in England was opened in 1764. Prior to this time, the majority of cloth produced in England was wool. Cotton requires more extensive processing to create fabric and thus was better suited to an industrial approach. In 1769, Richard Arkwright (1733–1792) patented the water frame, a machine that used water power to spin cotton into thread. In 1771, Arkwright installed the water frame in his cotton mill; this created one of the first factories that was constructed to house machinery; previous factories were primarily designed to bring workers together into one place.
These and other technological developments in the 1770s and 1780s made the British textile industry possible and highly successful. This technology was carefully protected by the British government; export of textile machinery was forbidden, and textile workers were prohibited from sharing information or leaving Britain. Samuel Slater (1768–1835) was born in England and apprenticed in a cotton factory partly owned by Richard Arkwright; during his apprenticeship, he memorized the technical details of the factory's machinery. He became aware that the United States was offering to pay for information on textile manufacturing, and in 1789 immigrated to the United States disguised as a farmer. With the financial backing of Moses Brown, a merchant, he built America's first waterpowered spinning mill in Pawtucket, Rhode Island. Slater employed families, including women and children, in this and subsequent mills that he constructed.
Slater's acquisition and use of technological information that its original owners wished to keep secret is an example of industrial espionage. Industrial espionage is a practice with a long history that continues today.
One of the most famous American engineering developments associated with textiles was the invention of the cotton gin by the inventor Eli Whitney (1765–1825) in 1792; the cotton gin is a machine that removes seeds from cotton after it is picked. Figure 13 shows the internal machinery of Whitney’s cotton gin. Prior to the invention of the cotton gin, this job was done by hand. In addition to the development of the cotton gin, Eli Whitney promoted the idea of interchangeable parts for mechanical devices. Before the development of interchangeable parts, each part of an object was manufactured individually and fit together in a painstaking process. Interchangeable parts are standardized; this allows, for example, one screw in a machine or a gun to be replaced by another screw without the need for reshaping any parts.
Figure 6.13
Internal workings of the original cotton gin developed by Eli Whitney.
Mechanical Printing
The process of setting type remained largely unchanged for 400 years after 1480. Letter molds were cast by hand, and these molds were hand assembled into rows and pages of text.
The industrial revolution in the nineteenth century brought changes, first to the printing processes, and then to typesetting. Friedrich Koenig (1774–1833) invented a steam-powered printing press; the first commercial unit was sold to the London Times in 1814. This press is shown in Figure 14. This press could make 1100 impressions per hour, which was much faster than hand-operated presses could print; this technology facilitated the emergence of a daily newspaper that was widely circulated and read. In 1835, the first commercial web press was introduced; a web press prints on a continuous roll (web) of paper. In 1844, Richard Hoe (1812–1886) in the United States developed the rotary printing press (Figure 15). This press could print over 20,000 copies per hour.
Figure 6.14
Steam press invented by Friedrich Koenig in 1814.
Figure 6.15
Rotary printing press invented by Richard Hoe.
Steam Powered Transportation
The development of the steam engine had a revolutionary effect on mining and manufacturing. As human and animal power were replaced by steam power, resources and manufactured goods could be acquired more efficiently. By the end of the eighteenth century, steam engines had become viable power sources for boats and trains. This in turn had a dramatic impact on society; the ability to transport people and goods over long distances provided significant opportunities for economic growth. It also made possible the westward expansion of settler populations in the United States.
In the late eighteenth century, there was a significant amount of experimentation with methods to power a ship using a steam engine. Various propulsion methods were tried; these included paddles suspended from the rear of the boat and the screw propeller. Robert Fulton (1765–1815) was the first to successfully develop a steamship in the United States. In 1807, he completed construction of 146 foot-long steamboat. The boat was powered by a 24 horse-power Boulton and Watt engine. It used wood for fuel. The boat transported passengers and cargo between New York City and Albany, New York, much more quickly than a sail-powered boat could. The steamboat service became very profitable for Fulton and his financial backer, Robert Livingston (1746–1813).
The United States has an extensive network of navigable rivers. In particular, the Mis
sissippi River and its tributaries can be used to navigate much of the central United States. In 1811 and 1812, Fulton constructed a steamboat in Pittsburgh that traveled down the Ohio and Mississippi rivers to New Orleans. Livingston and Fulton had obtained a monopoly on steamboat travel in Louisiana; their steamboats were again very commercially successful. Their steamboats were the first of many that navigated the rivers of the United States. From 1815 through 1860, steamboats dominated transportation of goods and passengers on rivers. Throughout this time, there were significant improvements in engineering; by 1850, many steamboats could travel at 20 miles an hour. Figure 16 shows a painting of the steamboat Robert E. Lee; it was built in 1866, and set a record for the fastest trip between St. Louis and New Orleans. It was destroyed in 1882 when it caught fire 30 miles outside of New Orleans. (Boiler explosions and fires were fairly common occurrences on steamboats, which made them a somewhat dangerous mode of transportation and led to government safety regulations.)
Figure 6.16
Painting of the steamboat Robert E. Lee by August Norieri.
As important as was the development of steam-powered ships, the development of steam-powered railroads had a much greater effect on the United States economy in the later half of the nineteenth century. Trains came to be the dominant mode of transport during this time. The corporations that built and operated the railroad system were the largest corporations during this period and created significant wealth for their owners.
