Topic 12. Technical achievements of the late XIX - early XX century.

At the end of the 19th century, the “Age of electricity” began. If the first cars were created by self-taught masters, now science has powerfully interfered in the lives of people - the introduction of electric motors was the result of science. The "Age of Electricity" began with the invention of the dynamo; DC generator, it was created by a Belgian engineer Zinovy ​​Gramm in 1870. Due to the principle of reversibility, Gram's machine could work both as a generator and as an engine; it could easily be converted into an alternator. In the 1880s, Yugoslav Nikola Tesla, who worked in America at Westinghouse Electric, created a two-phase AC motor. At the same time, Russian electrician Mikhail Dolivo-Dobrovolsky, who worked in Germany at AEG, created an efficient three-phase electric motor. Now the problem of using electricity rested on the problem of current transmission over a distance. In 1891, the opening of the World Fair in Frankfurt. At the request of the organizers of this exhibition, Dolivo-Dobrovolsky created the first high voltage transmission line and a transformer to it; the order provided for such a short time that no tests were carried out; The system was turned on - and immediately earned. After this exhibition, Dolivo-Dobrovolsky became the leading electrical engineer of that time, and AEG became the largest producer of electrical engineering. Since that time, factories and plants began to move from steam engines to electric motors, large power plants and power lines appeared.

A great achievement in electrical engineering was the creation of electric lamps. In 1879, the American inventor Thomas Edison undertook to solve this problem; his staff did more than 6,000 experiments, testing various materials for the incandescent filament, bamboo fibers turned out to be the best material, and Edison's first light bulbs were “bamboo”. Only twenty years later, at the suggestion of the Russian engineer Lodygin, the filament was made of tungsten.

Power plants required very high-power engines; This problem was solved by the creation of steam turbines. In 1889, Swede Gustav Laval received a patent for a turbine, in which the steam flow rate reached 770 m / s. At the same time, the Englishman Charles Parsons created a multistage turbine; Parsons turbine was used not only in power plants, but also as an engine of high-speed ships, cruisers and ocean liners. Hydroelectric power stations also appeared, using hydraulic turbines created by the French engineer Benoit Fourneron in the 1930s. In 1884, the American Pelton patented a high-pressure jet turbine. Hydraulic turbines had very high efficiency, about 80%, and the energy received at hydroelectric stations was very cheap.

Simultaneously with the work on the creation of super-power engines, work was being done on small mobile engines. Initially, it was gas engines that worked on the lamp gas; they were intended for small businesses and craft workshops. The gas engine was an internal combustion engine, that is, the combustion of fuel was carried out directly in the cylinder and the products of combustion were pushing the piston. Work at high temperatures in the cylinder required a cooling and lubrication system; these problems were solved by the Belgian engineer Etienne Lenoir, who created the first gas engine in 1860.

However, the luminescent gas obtained from sawdust was expensive fuel, the more promising were the work on the engine, working on gasoline. The gasoline engine demanded the creation of a carburetor, a device for spraying fuel in the cylinder. The first efficient gasoline engine was created in 1883 by German engineer Julius Daimler. This engine has opened the era of automobiles; already in 1886, Daimler put his engine on a four-wheeled carriage. This machine was demonstrated at an exhibition in Paris, where French manufacturers Rene Panard and Etienne Levassor bought a license for its production. Panhard and Levassor used only Daimler engine; they created their car, equipping it with a clutch system, gearbox and rubber tires. It was the first real car; in 1894, he won the first Paris-Rouen car race. The following year, Levassor won the Paris-Bordeaux race in his car. “It was insane! - said the winner. “I was racing at a speed of 30 kilometers per hour!” However, Daimler himself decided to start producing cars; in 1890, he created the Daimler Motorn company, and ten years later, the company produced the first Mercedes car. Mercedes has become a classic car of the early 20th century; He had a four-cylinder engine with a capacity of 35 liters. with. and developed a speed of 70 km / h. This beautiful and reliable car was an incredible success, it marked the beginning of mass production of cars.

The K. p. D. Daimler engine was about 20%, the efficiency of steam engines did not exceed 13%. Meanwhile, according to the theory of heat engines developed by the French physicist Carnot, the efficiency of an ideal engine could reach 80%. The idea of ​​an ideal engine agitated the minds of many inventors; in the early 1990s, the young German engineer Rudolf Diesel tried to bring it to life. The idea of ​​a diesel engine was to compress air in a cylinder to a pressure of about 90 atmospheres, while the temperature reached 900 degrees; then fuel was injected into the cylinder; in this case, the engine cycle was obtained close to the ideal “Carnot cycle”. The diesel engine failed to fully realize its idea, due to technical difficulties, it was forced to lower the pressure in the cylinder to 35 atmospheres. Nevertheless, the first Diesel engine, which appeared in 1895, caused a sensation - its efficiency was 36%, twice as much as that of gasoline engines. Many companies sought to buy a license for the production of engines, and in 1898, Diesel became a millionaire. However, the production of engines required a high technological level, and for many years Diesel had to travel to different countries, setting up production of its engines.

The internal combustion engine was used not only in cars. In 1901, the American engineers Hart and Parr created the first tractor, in 1912 the Holt company mastered the production of tracked tractors, and by 1920, 200,000 tractors were already working on American farms. The tractor took over not only field work, its engine was used to drive threshers, mowers, mills and other agricultural machines. With the creation of the tractor began the massive mechanization of agriculture.

The appearance of the internal combustion engine has played a big role in the birth of aviation. At first they thought that it was enough to put the engine on a winged vehicle - and it would rise into the air. In 1894, the famous inventor of the machine gun Maxim built a huge plane with a wingspan of 32 meters and a weight of 3.5 tons - this car crashed when you first tried to take to the air. It turned out that the main problem of aeronautics is flight stability. This problem was solved by long experiments with models and gliders. Back in the 1870s, the Frenchman Peno created several small models powered by a rubber motor; the result of his experiments was the conclusion about the important role of the tail. In the 1890s, the German Otto Lilienthal made about 2 thousand flights on a glider designed by him. He ran a glider, balancing his body, and could be in the air for up to 30 seconds, flying during this time 100 meters. Experiments Lilienthal ended tragically, he could not cope with a gust of wind and crashed, falling from a height of 15 meters. The Wright brothers, owners of a bicycle workshop in the city of Dayton, continued the creation of the gliders. The Wright brothers introduced a vertical rudder, transverse rudder-ailerons and measured the lift of the wings by blowing in the wind tunnel invented by them. The glider built by the Wright brothers was well managed and could stay in the air for about a minute. In 1903, the Wright brothers put on a glider a small gasoline engine, which they made themselves, in their workshop. December 14, 1903 Wilbur Wright made the first motor flight, flying 32 meters; On December 17, the flight range reached 260 meters. These were the first flights in the world, before the Wright brothers more than one airplane could not fly into the air. Gradually increasing the power of the engine, the Wright brothers learned to fly on their own airplane; in October 1905, the plane stayed in the air for 38 minutes, circling 39 kilometers. However, the achievements of the Wright brothers went unnoticed, and their requests for help addressed to the government went unanswered. In the same year of 1905, the Wright brothers were forced to stop their flights due to lack of funds. In 1907, the Wrights visited France, where the public was very interested in the flights of the first aviators - although the flight range of the French aviators was measured only hundreds of meters, and their airplanes did not have ailerons. The stories and photos of the Wright brothers made such a sensation in France that its echo reached America and the government immediately placed an order for 100 thousand dollars for the Wrights. In 1908, the new Wright airplane made a flight of 2.5 hours. Orders for airplanes poured in from all directions, the Wright aircraft building company with a capital of $ 1 million was founded in New York. However, already in 1909, there were several disasters on the Wright, and disappointment ensued. The fact is that the Wright brothers' planes did not have a tail, and therefore often "nodded." French aviators were aware of the need for tail plumage from Peno's experiments; they soon borrowed ailerons from the Wright brothers and outdid their American counterparts. In 1909, Louis Bleriot flew across the English Channel. In the same year, Henri Farman created the first mass model of the airplane, the famous "Farman-3". This aircraft became the main training machine of the time and the first aroplan, which began to be mass-produced.

At the end of the XIX century, work continued on the creation of new means of communication; the telegraph was replaced by telephone and radio communications. The first experiments on the transmission of speech over a distance were carried out by the English inventor Reis in the 60s. In the 1970s, Alexander Bell, a Scot who emigrated to America and taught at a school for deaf and dumb children, and then at Boston University, became interested in these experiments. An acquaintance of the doctor suggested that Bella should use the human ear for experiments and brought him the ear from the corpse. Bell copied the eardrum, and by placing a metal membrane next to an electromagnet, he achieved satisfactory transmission of speech over short distances. In 1876, Bell took a patent for a telephone and in the same year sold more than 800 copies. The following year, Davis Hughes invented the microphone, and Edison used a transformer to transmit sound over long distances. In 1877, the first telephone station was built, Bell established a telephone manufacturing company, and 10 years later there were already 100,000 telephone sets in the USA.

When working on the phone, Edison had the idea to record the vibrations of the microphone membrane. He supplied the membrane with a needle that recorded vibrations on a cylinder covered with foil. So the phonograph appeared. In 1887, the American Emil Berliner replaced the cylinder with a round plate and created a gramophone. Gramophone discs could be easily copied, and soon a lot of sound recording companies appeared.

A new step in the development of communication was made with the invention of wireless. The scientific basis of radio communication was the theory of electromagnetic waves created by Maxwell. In 1886, Heinrich Hertz experimentally confirmed the existence of these waves using an instrument called a vibrator. In 1891, the French physicist Branly discovered that metal filings placed in a glass tube change resistance under the influence of electromagnetic waves. This device is called the coherer. In 1894, English physicist Lodge used a coherer to record the passage of waves, and the next year, Russian engineer Alexander Popov attached an antenna to the coherer and adapted it to receive signals emitted by Hertz's vibrator. In March 1896, Popov demonstrated his apparatus at a meeting of the Russian Physico-Chemical Society and transmitted signals over a distance of 250 meters. Simultaneously with Popov, a young Italian, Guglielmo Marconi, created his radio-telegraph unit; he was the first to patent this invention; and the following year organized a joint stock company for its use. In 1898, Marconi included a jigger, a device for amplifying antenna currents, in his receiver, which made it possible to increase the transmission distance to 85 miles and carry out transmission through the English Channel. In 1900, Marconi replaced the coherer with a magnetic detector and made radio communications across the Atlantic Ocean: President Roosevelt and King Edward VIII exchanged radio telegrams of welcome. In October 1907, the Marconi company opened the first radio telegraph station to the general public.

One of the remarkable achievements of this time was the creation of cinema. The appearance of the cinema was directly connected with the improvement of the photograph invented by Dager. The Englishman Maddox in 1871 developed a dry-blob-gelatin process, which reduced the shutter speed to 1/200 second. In 1877, the Pole Leo Varneke invented a roller camera with silver bromide paper tape. In 1888, German photographer Anshütz created an instant curtain shutter. After that, it was possible to take snapshots, and the whole problem was reduced to creating a hopping mechanism to take pictures at intervals of a split second. This mechanism and the first camera were created by the brothers Lumière in 1895. In December of this year, the first cinema was opened on Boulevard des Capucines in Paris. In 1896, the Lumieres traveled all the European capitals, showing their first movie; these tours were a huge success.

At the end of the XIX century. For the first time, substances called plastics are being created. In 1873, J. Hayett (USA) patented celluloid - the first of these substances, which entered into wide use. Before World War I, bakelite and other plastics were invented, which are called pheno plastics. The production of artificial fiber began after in 1884 a French engineer G. Chardonnay developed a method for producing a nitrosel; subsequently learned to produce rayon from rayon. In 1899, the Russian scientist I.L. Kondakov initiated the production of synthetic rubber.

The last decades of the XIX century. were a time of technical change in the construction business. The construction of high-rise buildings, or “skyscrapers,” as they were called, began in Chicago in the 1980s. XIX century. The first building of a new type is considered to be the 10-story house of a Chicago-based insurance company, built in 1883 by the architect W. Jenny, who used steel ceilings. Strengthening the walls with a steel frame, on which they began to lean on the beams of interfloor floors, made it possible to double the height of buildings. The tallest building of those times was the New York 58-storey skyscraper with a height of 228 meters, built in 1913. But the highest construction was the Eiffel Tower, a peculiar monument of the "century became." Erected by the French engineer Gustave Eiffel on the Field of Mars in Paris in connection with the World Exhibition of 1889, this openwork tower was 300 meters high.

Along with metal structures, reinforced concrete structures were widely used at this time. The person who discovered reinforced concrete is considered to be the French gardener Joseph Monier. As early as 1849, he made tubs for fruit trees with an iron wire frame. Continuing his experiments, in the 60s he patented several methods for the manufacture of pipes, tanks and slabs of concrete with iron fittings. The most important was his patent for reinforced concrete vaulted ceilings (1877).

The end of the XIX century was a time of rapid growth of the global railway network. From 1875 to 1917, the length of railways increased 4 times and reached 1.2 million kilometers. The famous construction sites of the time were the mainline Berlin-Baghdad and the Great Siberian Route; the length of the Siberian route to 1916 was 7.4 thousand kilometers. Steel rails were laid on the new railways, they crossed the world's greatest rivers, and giant steel bridges were erected on these rivers. The beginning of the “era of steel bridges”, as contemporaries expressed, was laid by the arch bridge of engineer J. Ids over the Mississippi River (1874) and the hanging Brooklyn bridge of the architect Röbling in New York (1883). The central span of the Brooklyn Bridge was about half a kilometer long. Powerful locomotives of the compounding system with multiple expansion and high steam superheating worked on the new roads. In the 90s, the first electric locomotives and electrified railways appeared in the USA and Germany.

The construction of railways required a multiple increase in steel production.In the years 1870-1900, steel production increased 17 times. In 1878, the English engineer S.J. Thomas introduced the Thomas method of casting iron into steel; this method allowed the use of phosphoric iron ores of Lorraine and provided the metallurgical industry of Germany with ore. In 1892, the French chemist A. Moissan created an electric arc furnace. In 1888, American engineer Charles M. Hall developed an electrolytic method for the production of aluminum, opening the way to the widespread use of aluminum in industry.

New technical capabilities led to the improvement of military technology. In 1887, the American Hiram Maxim created the first machine gun. The famous Maxim machine gun made 400 rounds per minute and was equivalent to a company of soldiers in firepower. There were quick-firing three-inch guns and heavy 12-inch guns with shells weighing 200-300 kg.

Particularly impressive were the changes in military shipbuilding. In the Crimean War (1853-1856) wooden sailing giants with hundreds of cannons on three battery decks still participated, while the weight of the heaviest shells was 30 kg at that time. In 1860, the first iron battleship Warrior was launched in England, and soon all the wooden ships were scrapped. The naval arms race began, England and France competed in the creation of more and more powerful battleships, later Germany and the USA joined this race. In 1881 the English battleship Inflexible was built with a displacement of 12 thousand tons; He had only 4 main-caliber guns, but these were colossal 16-inch caliber guns placed in rotating towers, the barrel length was 8 meters, and the weight of the projectile was 700 kg.After some time, all the leading naval powers began to build armadillos of this type (albeit mainly with 12-inch guns). The new stage of the arms race was caused by the appearance in 1906 of the English battleship Dreadnought; "Dreadnought" had a displacement of 18 thousand tons and ten 12-inch guns. Thanks to the steam turbine, he developed a speed of 21 knots. Before the power of the Dreadnought, all the former battleships were not capable, and the sea powers began building ships like the Dreadnought. In 1913, battleships of the type “Queen Elizabeth” with a displacement of 27 thousand tons with ten 15-inch guns appeared. This arms race naturally led to a world war."Dreadnought" had a displacement of 18 thousand tons and ten 12-inch guns. Thanks to the steam turbine, he developed a speed of 21 knots. Before the power of the Dreadnought, all the former battleships were not capable, and the sea powers began building ships like the Dreadnought. In 1913, battleships of the type “Queen Elizabeth” with a displacement of 27 thousand tons with ten 15-inch guns appeared. This arms race naturally led to a world war."Dreadnought" had a displacement of 18 thousand tons and ten 12-inch guns. Thanks to the steam turbine, he developed a speed of 21 knots. Before the power of the Dreadnought, all the former battleships were not capable, and the sea powers began building ships like the Dreadnought. In 1913, battleships of the type “Queen Elizabeth” with a displacement of 27 thousand tons with ten 15-inch guns appeared. This arms race naturally led to a world war.This arms race naturally led to a world war.This arms race naturally led to a world war.

The cause of the world war was the discrepancy between the real power of the European powers and the size of their possessions. England, taking the role of the leader of the industrial revolution, created a huge colonial empire and seized most of the resources needed by other countries. However, by the end of the 19th century, Germany had become the leader in technical and industrial development; Naturally, Germany sought to use its military and technical superiority for the new division of the world. In 1914, the First World War began. The German command hoped to defeat its opponents in a couple of months, but these calculations did not take into account the role of the then emerged weapon - the machine gun. The machine gun gave a decisive advantage to the defending side; The German offensive was halted and a long "trench war" began. Meanwhile,the English fleet blocked the German ports and interrupted the supply of food. In 1916, famine began in Germany and, which ultimately led to the disintegration of the rear, to revolution and to the defeat of Germany.