Most of the inhabitants of the land Galapogossov, except for feral animals, native to the western coast of South America. Although the wildlife on these islands emerged relatively recently, the animals had no difficulty get to the Galapagos Islands, as South America from them only 960 km. Not all animals have adapted to new conditions, many died. Those who managed to save lives, left no descendants. Over millions of years resulted in the selection these kinds have become a new, better adapted to new conditions.
Perhaps the most amazing sights the Galapagos Islands – a giant tortoise, after which the island got its name (from the Spanish. Galapago – Turtle). Turtles densely populated island, without exception. The first of these hardy reptiles, probably sailed from the mainland. Weight of these "prehistoric monsters," sometimes as high as 300 kg. To a man they are safe, but when they are someone approaching with a hiss bury their heads in the shell. However, these armor-clad giants, no stranger to passion. During mating season males often throw themselves at each other, but at the last minute draw in the head shell.
Females lay up to 10 eggs in deep holes in wet soil. 13 months later cherepashata come to light. On only a lucky break to help them survive. If cherepashonok be able to dig their way out of the nest, sealed caked with dirt, then later it can become easy prey for gulls and herons lie in wait.
Quality Welding To get a reliable connection, it is necessary to ensure similarity mechanical properties and, most importantly "full strength" materials to be welded and the weld is achieved by correct selection of the electrode. In this important part of the core and the coating. Often the required steel is formed by the interaction melt and alloying additions. If you are working melts the electrode, picked his mark, if in an inert environment – the filler wire. When bad combination of materials seam is unstable or do not, cracking during cooling. Argon-arc welding (TIG) occurs in the inert gas argon (Ar). Usually use non-consumable tungsten electrode and the consumable filler wire in a convenient form of segments of length.
Gas is supplied from a special container. In addition to argon, helium is used (He) or a mixture of these gases. Method is highly versatile, high-quality weld seam and allows very fine details. Disadvantages – awkwardness equipment and difficulty of working outdoors, where the necessary measures against the blowing gas protection. Provides the best quality of argon, helium has the worst qualities – a drop of melt in its midst heavily sprayed. SEMI-AUTOMATIC welding in CO2 (MIG) Allows you to replace the piece electrode wire of solid section. Carbon dioxide is good when you do not need a very high quality, as it slightly reduces the strength properties of steel and leads to its spattering. Most important advantage of the method – the cheapness of materials. Compared with CO2 uniqueness of argon that the relatively low current (200 A), it allows for spray transfer of metal characterized by a high utilization factor (the ratio of the masses caught in the seam of the metal to the mass consumed) – 0,8-0,85.