Oil is an oily liquid with a characteristic spicy smell and different, depending on the place of production, color. According to its chemical structure, it is an extremely complex mixture of different chemical compounds, especially organic substances - hydrocarbons. Hydrocarbons are called so because they represent a simple chemical compounds of elements: carbon and hydrogen. On top of that oil is composed of sulfur, nitrogen, oxygen and other impurities (including water and sand). Despite the fact that hydrocarbons include only two elements, the number of them is enormous. This is because the carbon and hydrogen may be joined together in many different combinations and proportions. Therefore, the properties of hydrocarbons is very different, and their study is a large section of chemistry - chemistry of organic substances.

Steam Hammer prevailed in engineering for 90 years and was one of the most important cars of its time. His creation and introduction into production of its significance to the industrial revolution can be compared only with the introduction of mechanized carriage lathe implemented Henry Mawdsley at the turn of the XIX century. The important place occupied by the hammer in the chain of production, due to great importance in forging a general process of obtaining products of iron. As already mentioned, the emergence of forged syrodutnym way connected with the recovery of iron. Kritsa soft iron extracted from domnitsy had loose porous structure. Its pores were filled with slag. To obtain high-quality iron and steel for the manufacture of tools, should remove the slag, and then welded. This is precisely achieved by forging. Forge metal could just heating it up to welding heat: strikes, strikes the hammer was to be the most powerful to welding in bundles actually occurred, and no cavities were formed. In addition, the hot metal slog squeeze the remains of slag, which also improves the quality of iron. Only well prokovanny metal godilsya then for the production of tools and weapons, and for many centuries, they also produced exclusively by forging. Later, in the XVIII-XIX centuries - and hammer out the details of machines.

Since ancient times, one of the main lessons rights were gathering. That word modern scientists to collect edible seeds imply, nuts, fruits, roots, larvae, eggs, etc. The main tool in the gathering were billet-digger, one end of which the focus was on fire and burnt to strength. But already in very ancient times, along with it has become used a stick with transverse knots, more convenient for digging the earth. In this gear, you can see a prototype of hoes. Later, the working part of the sticks were made of horn or bone. Finally there were the stone hoes, planted on a wooden handle. This tool can trench the ground, flip it and break komya. When people moved to the cultural cultivation of plants, hoe over several millennia, agriculture remains the principal tool for farmers.

One of the most remarkable events in the history of technology is the emergence in the mid XIX century skoropechatnoy a rotating machine that allowed thousands of times to increase the production of publications, especially newspapers and magazines. This invention, in the same way as the establishment at that time Gutenberg first typographic machine, had an enormous impact on all aspects of the life of mankind. Indeed, the rapid development of education and its dissemination in the masses of people, in the XVIII-XIX centuries, creating a huge demand for the printed word, which led to an increase in circulation of books and newspapers. Meanwhile, an old printing press has undergone very little change from the XVI century and was poorly suited to meet the demand overdue. Many printer in the XVIII century puzzle over how to increase productivity and create skoropechatnuyu car. The right way was eventually found Friedrich Koenig, the son of poor farmer Prussia. Fifteen years later he entered an apprentice in a printing house, and since that time all his life has been associated with printed matter. Back in 1794, Koenig made the first improvement, creating a model of printing machine, continuous, with the help of gear wheels, lifting and lowering piana (press). But many years passed before he was able to use his invention to practice. All owners of German printers to which Koenig approached for support, refusal to meet him. In 1806 he moved to London, and only here for his invention paid attention.