Re previous post ...
chain saw / chainsaw
The origin is debated, but two important contributors to the chainsaw are Joseph Buford Cox and Andreas Stihl; the latter patented and developed a chainsaw in 1926 and a gasoline-powered chainsaw in 1929, and founded a company to mass-produce them.
In 1927, Emil Lerp, the founder of Dolmar, developed the world's first gasoline-powered chainsaw and mass-produced them. McCulloch and Industrial Equipment Corp in North America started to produce chainsaws.
The early models were heavy, two-person devices with long bars. Often chainsaws were so heavy that they had wheels like dragsaws. Other outfits used driven lines from a wheeled power unit to drive the cutting bar. After WW2, improvements in aluminum and engine design lightened chainsaws to the point where one person could carry them. In some areas the skidder / chainsaw crews have been largely replaced by the feller buncher and harvester.