Lecture 6 min.
The inventors of the machines that brought about the Industrial Revolution were not scientists — they were self-taught craftsmen. Some of them were illiterate; Stephenson, for instance, did not learn to read until the age of 18. During the Industrial Revolution, science and technology developed independently of one another. This was especially true of mathematics: it was during this period that vector analysis emerged, the French mathematician A. Cauchy created the theory of functions of a complex variable, and the Englishman W. Hamilton and the German H. Grassmann created vector algebra. In the works of Laplace, Legendre, and Poisson, probability theory was developed. The main achievements of physics were connected with the study of electricity and magnetism. At the turn of the 18th–19th centuries, the Italian physicist Volta created the galvanic battery; batteries of this kind remained for a long time the only source of electric current and an essential element of every experiment. In 1820, the Danish physicist H. Oersted discovered that an electric current acts on a magnetic needle; then the Frenchman A. Ampère established that a magnetic field arises around a conductor and that forces of attraction or repulsion appear between two conductors. In 1831, Michael Faraday discovered the phenomenon of electromagnetic induction. This phenomenon consists in the fact that if a closed conductor crosses magnetic lines of force as it moves, an electric current is induced in it. In 1833, the German scientist Emil Lenz, working in Russia, created a general theory of electromagnetic induction. In 1841, Joule studied the effect of heat release when an electric current passes through a conductor. In 1865, the outstanding English scientist James Maxwell created the theory of the electromagnetic field.
The theory of electromagnetism became the first field in which scientific discoveries began to be applied directly in technology. In 1832, the Russian subject Baron P. Schilling demonstrated the first model of an electric telegraph. In Schilling's device, pulses of electric current caused the deflection of a needle corresponding to a particular letter. In 1837, the American Morse created an improved telegraph, in which transmitted messages were recorded on a paper tape using a special code. However, it took six years before the American government appreciated this invention and allocated funds for the construction of the first telegraph line between Washington and Baltimore. After that, the telegraph began to develop rapidly: in 1850, a telegraph cable connected London and Paris, and in 1858, a cable was laid across the Atlantic Ocean.
At the end of the 18th century, a new science was born — chemistry. Previously, alchemists believed that all substances consisted of four elements: fire, air, water, and earth. In 1789, Antoine Lavoisier experimentally proved the law of conservation of mass. Then John Dalton proposed the atomic theory of the structure of matter; he argued that atoms of different substances have different weights and that chemical compounds are formed by the combination of atoms in certain numerical ratios. In 1809, the law of combining volumes in the chemical interaction of gases was discovered. This phenomenon was explained by Dalton and Gay-Lussac as evidence that equal volumes of gas contain equal numbers of molecules. Later, Avogadro put forward the hypothesis that a given volume (say, a cubic meter) of any gas contains the same number of molecules; this hypothesis was experimentally confirmed in the 1840s by the French chemist C. Gerhardt. In 1852, the English chemist E. Frankland introduced the concept of valence — that is, a numerical expression of the ability of atoms of different elements to form chemical compounds with one another. In 1869, D. I. Mendeleev created the periodic table of elements.
In the first half of the 19th century, the chemical industry produced mainly sulfuric acid, soda, and chlorine. In 1785, Claude Berthollet proposed bleaching fabrics with chlorinated lime. In 1842, the Russian chemist Nikolai Zinin synthesized the first artificial dye, aniline. In the 1850s, the German chemist A. Hofmann and his student W. Perkin obtained two other aniline dyes, rosaniline and mauveine. This work made possible the creation of an aniline dye industry, which developed rapidly in Germany. Another important branch of the chemical industry was the production of explosives. In 1845, the Swiss chemist Schönbein invented guncotton, and the Italian Sobrero invented nitroglycerin. In 1862, the Swede Alfred Nobel set up industrial production of nitroglycerin, and later moved on to the production of dynamite.
In the 1840s, the German chemist Justus von Liebig established the principles of using mineral fertilizers in agriculture. From that time on, the production of superphosphate and potassium fertilizers began, and Germany became the center of the European chemical industry.
One of the achievements of experimental chemistry was the invention of photography. In the 18th century, an attraction using the camera obscura was widespread. It was a box with a small hole into which a magnifying glass was inserted; on the opposite wall one could see an image of the objects placed in front of the camera. In the 1820s, the French artist Joseph Niépce attempted to capture this image. Having coated a copper plate with a layer of bitumen, he placed it in the camera; the plate was then treated with various chemicals to develop the image. Everything depended on the choice of the light-sensitive layer, the developer, and the fixer. Years of experimentation were required, which, after Niépce's death, were continued by his assistant Louis Daguerre. By 1839, Daguerre had succeeded in obtaining an image on plates coated with silver iodide after developing them with mercury vapor; thus daguerreotype was born. The French government recognized this invention and granted Daguerre a lifetime pension of 6,000 francs.
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