Second Industrial Revolution - Technology

Technology

By the middle of the 19th century there was a scientific understanding of chemistry and a fundamental understanding of thermodynamics and by the last quarter of the century both of these sciences were near their present day basic form. Thermodynamic principles were used in the development of physical chemistry. Understanding chemistry and thermodynamics greatly aided the development of basic inorganic chemical manufacturing and the aniline dye industries.

Control theory is the basis for process control, which is used in many forms of automation, particularly for process industries such as oil refining, paper and chemical manufacturing and for controlling ships and airplanes. Control theory was developed to analyze the functioning of centrifugal governors on steam engines. These governors had been used on wind and water mills to correctly position the gap between mill stones with changes in speed. The governor was adapted to steam engines by James Watt. Improved versions were used to stabilize automatic tracking mechanisms of telescopes and to control speed of ship propellers and rudders. However, these governors were sluggish and oscillated around the set point. James Clerk Maxwell wrote a paper mathematically analyzing the actions of governors, which marked the beginning of the formal development of control theory. The science was continually improved and evolved into an engineering discipline. See: Control system

Another beneficiary of chemistry was steel making with development of the Gilchrist-Thomas process (or basic Bessemer process) which involved lining the converter with limestone or dolomite to remove phosphorus, an impurity in most iron ores. Chemistry also benefited metallurgy by identifying and developing processes for purifying various elements such as chromium, molybdenum, titanium, vanadium and nickel which could be used for making alloys with special properties, especially with steel. Vanadium steel, for example, is strong and fatigue resistant, and was used in half the automotive steel. Other important alloys are used in high temperatures, such as steam turbine blades, and stainless steels for corrosion resistance.

The developing science of metallurgy was able to solve the problem of rail failure in the US by the mid-1880s by properly controlling the temperature of steel while rolling into rails, although this had been understood in Europe some decades earlier.

One of the most important developments of chemistry was the Haber process for producing ammonia (ca. 1913); however, the process did not become widespread until WWII. Today, the world food supply is critically dependent on inexpensive nitrogen fertilizers produced by the Haber-Bosch process.

The Corliss steam engine (1849) was a significant improvement in efficiency, and later steam engines were designed with multiple expansions (stages) which resulted in even greater efficiency. The steam turbine was developed by Charles Parsons in 1884. Unlike steam engines, the turbine produced rotary power rather than reciprocating power that required a crank and heavy flywheel. The large number of stages of the turbine allowed for high efficiency and reduced size by 90%. The turbine's first application was in shipping followed by electric generation in 1903.

The first widely used internal combustion engine was the Otto type (1876). From the 1880s until electrification it was successful in small shops because small steam engines were inefficient and required too much operator attention. The Otto engine soon began being used to power automobiles, and remains as today's common gasoline engine.

The diesel engine was designed by Rudolf Diesel in 1897 using thermodynamic principles with the specific intention of being highly efficient. It took several years to perfect and become popular, but found application in shipping before powering locomotives. It remains the world's most efficient prime mover.

One of the most important scientific advancements in all of history was the unification of light, electricity and magnetism through Maxwell's electromagnetic theory. A scientific understanding of electricity was necessary for the development of efficient electric generators, motors and transformers. Heinrich Hertz's 1887 experiments confirmed and explored the phenomenon of electromagnetic waves that had been predicted by Maxwell. This led to the development of radio before the end of the 2nd I.R., but radio was mainly used in shipping until the early 1920s when commercial broadcasts began. Radio as we know it depended on the development of the vacuum tube (thermionic valve) (ca. 1906-08) which allowed amplification. The vacuum tube was essential for most electronics until the transistor became available in the 1950s.

Electrification was called "the most important engineering achievement of the 20th century" by the National Academy of Engineering. In 1881, Sir Joseph Swan, inventor of the first feasible incandescent light bulb, supplied about 1,200 Swan incandescent lamps to the Savoy Theatre in the City of Westminister, London, which was the first theatre, and the first public building in the world, to be lit entirely by electricity. Electricity was used for street lighting in the early 1880s. Electric lighting in factories greatly improved working conditions, eliminating the heat and pollution caused by gas lighting, and reducing the fire hazard to the extent that cost of electricity for lighting was often offset by the reduction in fire insurance premiums. Frank J. Sprague developed the first successful DC motor in 1886 which he successfully adapted to power street railways, and by 1889 there were 110 electric railways either in operation and using his equipment or in planning. The electric street railway became a major infrastructure before 1920. AC motors were developed by Nikola Tesla (Westinghouse) and others in the 1890s and soon began to be used in the electrification of industry. Household electrification did not become common until the 1920s, and then only in cities. Fluorescent lighting was commercially introduced at the 1939 World's Fair.

Telegraph lines were installed along rail lines for communicating with trains, and evolved into a communications network. The first commercial electrical telegraph was co-developed by Charles Wheatstone and William Fothergill Cooke, and was first successfully demonstrated on 25 July 1837 between Euston railway station and Camden Town in London. The first lasting transatlantic telegraph cable was laid by Isambard Kingdom Brunel's ship the SS Great Eastern in 1866. By the 1890s there was a telegraph network connecting major cities worldwide, which greatly facilitated international commerce, travel and diplomacy.

The telephone was patented in 1876, and like the early telegraph, it was used mainly to speed business transactions.

The tabulating machine, which read data stored on punched cards by allowing electrical contact through the holes and keeping running totals with electro-mechanical counters, was invented by Herman Hollerith in the mid 1880s. Tabulating machines were used for the US 1890 census, which was completed in less than a year and at great reduction in labor compared to the 8 years for the 1880 census using hand counts. Hollerith founded a company to make and lease the machines. It was renamed "International Business Machines" (IBM) in 1924. Tabulating machines and other unit record equipment was widely used by census bureaus, insurance companies, railroads and numerous other businesses. Unit record equipment remained the dominant form of data management until the 1960s.

Studies by biologists led farmers such as Henry A. Wallace to use genetic biology to create hybrid corn in the 1920s. It was the first application of biotechnology and was followed by the Green revolution.

The germ theory of disease was developed and was accompanied by advances in microbiology, such as staining bacteria to make them identifiable under a microscope.