Rus Articles Journal

Who determined height of Elbrus and level of the Caspian Sea?

In structure of the expedition going in 1823 on a shlyupa " Enterprise; in global cruise, according to the recommendation of professors of Derptsky (Tartu) university it was included as the physicist 19 - the summer student Emili Lenz. The oceanographic, meteorological and geophysical supervision received and analysed by it in four years of swimming in the Atlantic, Quiet and Indian oceans were published and received high appreciation of experts.

For these achievements in May, 1828 Lenz was elected the graduated in a military academy of Academy of Sciences on physics. In 1829 took part in expedition to the Caucasus where took magnetic, thermometric and barometric measurements. Lenz was a participant of the first climbing Elbrus and determined by a barometric way its height. In the same way he established that the level of the Caspian Sea is 30,5 m lower Black.

In 1830 it was appointed the extraordinary academician and the director of a physical office at St. Petersburg AN, in 1834 - the ordinary academician. In 1836 headed department of physics at the St. Petersburg university, and in 1863 became the rector of this university. Lenz paid much attention to teaching activity, and not only at university, but also at Teacher training college where Mendeleyev was his pupil.

From 1831 to 1836 Lenz was engaged in electromagnetism studying. It opened the law of induction ( Lenz`s Law ), on which the direction of induction current always such is that it interferes with that action by which he is called. Irrespective of Joule established that the amount of heat allocated by current in the conductor in proportion to a square of current and resistance of the conductor ( Joule-Lenz law ) .

Together with Jacobi, Lenz for the first time developed methods of calculation of electromagnets in electrical machines, established existence in the last reactions of an anchor . Opened reversibility of electrical machines. Besides, he studied dependence of resistance of metals on temperature. One of the first foreign scientists Lenz highly appreciated scientific achievements of Ohm.

At the same time Lenz continued to go in for physical geography. He studies a crust structure, an origin and movement of the breeds forming it and shows that it continuously changes and that this process influences a relief of continents. He established three major factors causing continuous change of a land surface - influence of volcanic forces, influence of waters with assistance of the atmosphere and influence of organic beings. Lenz opened important regularities of the daily and annual course of temperature and pressure of air, wind activity, evaporation of water, condensation of water vapor and formation of clouds, electric and optical phenomena in the atmosphere.

These researches in 1851 were published in the form of fundamental work of Lenz Physical geography which was repeatedly republished further in Russia and abroad. And it The Management to physics made for the Russian gymnasiums (1839), it was republished 11 times.

On February 24, 2008 204 years since birth Aemilia of Khristianovich of Lenz are executed. Its works made the significant contribution to further development of both physical geography, and electrical equipment. Lenz in Rome where he went to be treated died on February 10, 1865. There it is also buried.]