Ancient era

The Ancient Romans built aqueducts to bring a steady supply of

The pyramids in ancient Egypt, ziggurats of Mesopotamia, the Acropolis and Parthenon in Greece,
the Roman aqueducts, Via Appia and Colosseum, Teotihuacán, and the Brihadeeswarar
Temple of Thanjavur, among many others, stand as a testament to the ingenuity and skill of ancient
civil and military engineers. Other monuments, no longer standing, such as the Hanging Gardens of
Babylon and the Pharos of Alexandria, were important engineering achievements of their time and
were considered among the Seven Wonders of the Ancient World.

The six classic simple machines were known in the ancient Near East. The wedge and the inclined
plane (ramp) were known since prehistoric times.[9] The wheel, along with the wheel and
axle mechanism, was invented in Mesopotamia (modern Iraq) during the 5th millennium BC.
[10]
The lever mechanism first appeared around 5,000 years ago in the Near East, where it was used in
a simple balance scale,[11] and to move large objects in ancient Egyptian technology.[12] The lever was
also used in the shadoof water-lifting device, the first crane machine, which appeared in
Mesopotamia c. 3000 BC,[11] and then in ancient Egyptian technology c. 2000 BC.[13] The earliest
evidence of pulleys date back to Mesopotamia in the early 2nd millennium BC,[14] and ancient
Egypt during the Twelfth Dynasty (1991–1802 BC).[15] The screw, the last of the simple machines to
be invented,[16] first appeared in Mesopotamia during the Neo-Assyrian period (911–609) BC.
[14]
The Egyptian pyramids were built using three of the six simple machines, the inclined plane, the
wedge, and the lever, to create structures like the Great Pyramid of Giza.[17]

The earliest civil engineer known by name is Imhotep.[6] As one of the officials of
the Pharaoh, Djosèr, he probably designed and supervised the construction of the Pyramid of
Djoser (the Step Pyramid) at Saqqara in Egypt around 2630–2611 BC.[18] The earliest practical water-
powered machines, the water wheel and watermill, first appeared in the Persian Empire, in what are
now Iraq and Iran, by the early 4th century BC.[19]

Kush developed the Sakia during the 4th century BC, which relied on animal power instead of human
energy.[20] Hafirs were developed as a type of reservoir in Kush to store and contain water as well as
boost irrigation.[21] Sappers were employed to build causeways during military campaigns.[22] Kushite
ancestors built speos during the Bronze Age between 3700 and 3250 BC.[23] Bloomeries and blast
furnaces were also created during the 7th centuries BC in Kush.[24][25][26][27]

Ancient Greece developed machines in both civilian and military domains. The Antikythera
mechanism, an early known mechanical analog computer,[28][29] and the
mechanical inventions of Archimedes, are examples of Greek mechanical engineering. Some of
Archimedes' inventions, as well as the Antikythera mechanism, required sophisticated knowledge
of differential gearing or epicyclic gearing, two key principles in machine theory that helped design
the gear trains of the Industrial Revolution, and are widely used in fields such
as robotics and automotive engineering.[30]
Ancient Chinese, Greek, Roman and Hunnic armies employed military machines and inventions such
as artillery which was developed by the Greeks around the 4th century BC, [31] the trireme,
the ballista and the catapult, the trebuchet by Chinese circa 6th-5th century BCE.[32]

Middle Ages

The earliest practical wind-powered machines, the windmill and wind pump, first appeared in
the Muslim world during the Islamic Golden Age, in what are now Iran, Afghanistan, and Pakistan, by
the 9th century AD.[33][34][35][36] The earliest practical steam-powered machine was a steam jack driven
by a steam turbine, described in 1551 by Taqi al-Din Muhammad ibn Ma'ruf in Ottoman Egypt.[37][38]

The cotton gin was invented in India by the 6th century AD,[39] and the spinning wheel was invented
in the Islamic world by the early 11th century,[40] both of which were fundamental to the growth of
the cotton industry. The spinning wheel was also a precursor to the spinning jenny, which was a key
development during the early Industrial Revolution in the 18th century.[41]

The earliest programmable machines were developed in the Muslim world. A music sequencer, a
programmable musical instrument, was the earliest type of programmable machine. The first music
sequencer was an automated flute player invented by the Banu Musa brothers, described in
their Book of Ingenious Devices, in the 9th century.[42][43] In 1206, Al-Jazari invented
programmable automata/robots. He described four automaton musicians, including drummers
operated by a programmable drum machine, where they could be made to play different rhythms
and different drum patterns.[44]

A water-powered mine hoist used for raising ore, Germany, c. 1556

Before the development of modern engineering, mathematics was used by artisans and craftsmen,
such as millwrights, clockmakers, instrument makers and surveyors. Aside from these professions,
universities were not believed to have had much practical significance to technology. [45]: 32

A standard reference for the state of mechanical arts during the Renaissance is given in the mining
engineering treatise De re metallica (1556), which also contains sections on geology, mining, and
chemistry. De re metallica was the standard chemistry reference for the next 180 years.[45]

Modern era
 The application of the steam engine allowed coke to be
substituted for charcoal in iron making, lowering the cost of iron, which provided engineers with a
new material for building bridges. This bridge was made of cast iron, which was soon displaced by
less brittle wrought iron as a structural material.

The science of classical mechanics, sometimes called Newtonian mechanics, formed the scientific
basis of much of modern engineering.[45] With the rise of engineering as a profession in the 18th
century, the term became more narrowly applied to fields in which mathematics and science were
applied to these ends. Similarly, in addition to military and civil engineering, the fields then known as
the mechanic arts became incorporated into engineering.

Canal building was an important engineering work during the early phases of the Industrial
Revolution.[46]

John Smeaton was the first self-proclaimed civil engineer and is often regarded as the "father" of
civil engineering. He was an English civil engineer responsible for the design of bridges,
canals, harbors, and lighthouses. He was also a capable mechanical engineer and an
eminent physicist. Using a model water wheel, Smeaton conducted experiments for seven years,
determining ways to increase efficiency.[47]: 127 Smeaton introduced iron axles and gears to water
wheels.[45]: 69 Smeaton also made mechanical improvements to the Newcomen steam engine.
Smeaton designed the third Eddystone Lighthouse (1755–59) where he pioneered the use of
'hydraulic lime' (a form of mortar which will set under water) and developed a technique involving
dovetailed blocks of granite in the building of the lighthouse. He is important in the history,
rediscovery of, and development of modern cement, because he identified the compositional
requirements needed to obtain "hydraulicity" in lime; work which led ultimately to the invention
of Portland cement.

Applied science led to the development of the steam engine. The sequence of events began with the
invention of the barometer and the measurement of atmospheric pressure by Evangelista
Torricelli in 1643, demonstration of the force of atmospheric pressure by Otto von Guericke using
the Magdeburg hemispheres in 1656, laboratory experiments by Denis Papin, who built
experimental model steam engines and demonstrated the use of a piston, which he published in
1707. Edward Somerset, 2nd Marquess of Worcester published a book of 100 inventions containing
a method for raising waters similar to a coffee percolator. Samuel Morland, a mathematician and
inventor who worked on pumps, left notes at the Vauxhall Ordinance Office on a steam pump design
that Thomas Savery read. In 1698 Savery built a steam pump called "The Miner's Friend". It
employed both vacuum and pressure.[48] Iron merchant Thomas Newcomen, who built the first
commercial piston steam engine in 1712, was not known to have any scientific training. [47]: 32
 Jumbo Jet

The application of steam-powered cast iron blowing cylinders for providing pressurized air for blast
furnaces lead to a large increase in iron production in the late 18th century. The higher furnace
temperatures made possible with steam-powered blast allowed for the use of more lime in blast
furnaces, which enabled the transition from charcoal to coke.[49] These innovations lowered the cost
of iron, making horse railways and iron bridges practical. The puddling process, patented by Henry
Cort in 1784 produced large scale quantities of wrought iron. Hot blast, patented by James
Beaumont Neilson in 1828, greatly lowered the amount of fuel needed to smelt iron. With the
development of the high pressure steam engine, the power to weight ratio of steam engines made
practical steamboats and locomotives possible.[50] New steel making processes, such as the Bessemer
process and the open hearth furnace, ushered in an area of heavy engineering in the late 19th
century.

One of the most famous engineers of the mid-19th century was Isambard Kingdom Brunel, who built
railroads, dockyards and steamships.

Offshore platform, Gulf of Mexico

The Industrial Revolution created a demand for machinery with metal parts, which led to the
development of several machine tools. Boring cast iron cylinders with precision was not possible
until John Wilkinson invented his boring machine, which is considered the first machine tool.
[51]
Other machine tools included the screw cutting lathe, milling machine, turret lathe and the metal
planer. Precision machining techniques were developed in the first half of the 19th century. These
included the use of gigs to guide the machining tool over the work and fixtures to hold the work in
the proper position. Machine tools and machining techniques capable of producing interchangeable
parts lead to large scale factory production by the late 19th century.[52]

The United States Census of 1850 listed the occupation of "engineer" for the first time with a count
of 2,000.[53] There were fewer than 50 engineering graduates in the U.S. before 1865. The first PhD in
engineering (technically, applied science and engineering) awarded in the United States went
to Josiah Willard Gibbs at Yale University in 1863; it was also the second PhD awarded in science in
the U.S.[54] In 1870 there were a dozen U.S. mechanical engineering graduates, with that number
increasing to 43 per year in 1875. In 1890, there were 6,000 engineers in civil, mining, mechanical
and electrical.[50] There was no chair of applied mechanism and applied mechanics at Cambridge until
1875, and no chair of engineering at Oxford until 1907. Germany established technical universities
earlier.[55]

The foundations of electrical engineering in the 1800s included the experiments of Alessandro
Volta, Michael Faraday, Georg Ohm and others and the invention of the electric telegraph in 1816
and the electric motor in 1872. The theoretical work of James Maxwell (see: Maxwell's equations)
and Heinrich Hertz in the late 19th century gave rise to the field of electronics. The later inventions
of the vacuum tube and the transistor further accelerated the development of electronics to such an
extent that electrical and electronics engineers currently outnumber their colleagues of any other
engineering specialty.[6] Chemical engineering developed in the late nineteenth century.[6] Industrial
scale manufacturing demanded new materials and new processes and by 1880 the need for large
scale production of chemicals was such that a new industry was created, dedicated to the
development and large scale manufacturing of chemicals in new industrial plants. [6] The role of the
chemical engineer was the design of these chemical plants and processes. [6] Originally deriving from
the manufacture of ceramics and its putative derivative metallurgy, materials science is one of the
oldest forms of engineering.[56] Modern materials science evolved directly from metallurgy, which
itself evolved from the use of fire. Important elements of modern materials science were products of
the Space Race; the understanding and engineering of the metallic alloys,
and silica and carbon materials, used in building space vehicles enabling the exploration of space.
Materials science has driven, and been driven by, the development of revolutionary technologies
such as rubbers, plastics, semiconductors, and biomaterials.

The solar furnace at Odeillo in the Pyrénées-

Aeronautical engineering deals with aircraft design process design while aerospace engineering is a
more modern term that expands the reach of the discipline by including spacecraft design. Its origins
can be traced back to the aviation pioneers around the start of the 20th century although the work
of Sir George Cayley has recently been dated as being from the last decade of the 18th century. Early
knowledge of aeronautical engineering was largely empirical with some concepts and skills imported
from other branches of engineering.[57] Only a decade after the successful flights by the Wright
brothers, there was extensive development of aeronautical engineering through development of
military aircraft that were used in World War I. Meanwhile, research to provide fundamental
background science continued by combining theoretical physics with experiments.

Main branches of engineering