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.
How to Use a Reciprocating Saw and Jigsaw. A jigsaw is a type of reciprocating saw; learn the differences and tips for using these tools. The reciprocal saw uses a reciprocating, or alternating direction, motor to move a blade back and forth.Blades are available for cutting wood, metal, plastic, and drywall or plaster.