Chainsaws
By the 1930s, chainsaws were replacing manual crosscut saws as they greatly reduced the time and effort required to fell a tree.
A chainsaw is a powerful hand-held, engine driven tool for cutting wood. It has a metal chain with cutting teeth that moves around a guide bar. Lubricating oil drips continually onto the chain to prevent it from sticking. At first, chainsaws were awkward
two-man machines.

In the 1940s, chainsaws became quieter, lighter, smaller, and safer to operate by one person.