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.
A typical chain tool. With a chain placed on the central sprocket, the screw is turned until a pin is pushed from the linkage. A chain tool is a small mechanical device used to break a bicycle chain in such a way that it can be mended with the same tool. A bicycle chain has links and plates that are pinned together; these pins can be pushed out with the chain tool. Because the pins are pushed out gradually with a screw, they can be partially removed or fully removed, depending upon the intention of the user.