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 chainsaw can be a boon for a homeowner who wants to keep his yard as manicured as possible. It can make pruning jobs a snap, reduce logs to manageable sizes and cut firewood. Not all chainsaws are created equal, however. Consider a few factors before deciding which size of chainsaw you need.