The stratosphere (/ËstrÃ¦tÉËsfÉªÉr, -toÊ-/) is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. About 20% of the atmosphere's mass is contained in the stratosphere.
The chainsaw is a highly effective and efficient tree and branch cutting power tool. It works with an engine, referred to as a power head; powering a metal chain, driven by a centrifugal clutch, with a chain moving around a groove in the guide bar at fast speeds.
Arc (Stick) Welding or SMAW (Shielded Metal Arc Welding): Arc welding is one of the oldest welding processes around. It can be the cheapest to start with as there is not a lot of equipment needed. It is also very versatile as there a lot of specialized electrodes available.