Chain saws-the forest primeval has seen few tools with such devastating utility, not to mention sheer volume. If a strong man with a felling axe needs at least forty whacks to take down a tree, a chain saw can do it in a matter of moments with a great deal less effort.
Chain saws are sold in both electric and gasoline-powered models. In general, the electric models are smaller and less powerful (and, obviously, limited by the availability of electrical current). But they are somewhat quieter than their gas-powered equivalents, and are very efficient tools, particularly for more precise trimming and cleanup work.
The gasoline-powered models run the gamut from convenient around-the-yard tools to those that will cut down a tree big enough to crush your house if it fell on it.
Both electric and gas models share a basic design. The motor drives a chain that rotates around a steel guide called the bar. The saw is controlled from a pistol grip handle (for the right hand) with a trigger throttle control. The operator's left hand balances the saw while gripping a handle or bar across the top of the saw.
The chain remains still when the motor is at idle, and a centrifugal clutch disengages and engages depending upon the speed of the motor.
Gas chain saws are powered by two-stroke engines, meaning that the engine oil is mixed with the gasoline. You need to get the mixture to the exact proportions specified by the saw's manufacturer, or you'll have difficulty keeping the saw running consistently and well.
The chain and bar must be kept properly oiled, too. There's a reservoir on the motor housing for chain oil, and it must be fed to the saw at frequent intervals, usually by means of a small button that pumps a few drops of oil onto the chain. Follow the instructions supplied with your saw.
The chain saw has come to be regarded as indispensable for a surprising variety of work. More than few “finishing” touches in log-cabin construction, for example, are done with chain saws cutting grooves or openings for windows and cabinets. Sculptors these days use chain saws, as do timber framers for certain kinds of rough shaping.
Be ever so careful with this tool. Don't cut upward with it, not ever, that's dangerous practice. Watch out for jams; they're hard on the tool and can put the sawyer in a predicament (“How am I going to get my twenty-pound tool loose from that two-ton tree?”). Never cut down trees with hanging branches, or that are braced against others.
Most important of all, don't imagine you're an expert too soon. Even pros who have felled a zillion trees are occasionally surprised by the fall of a tree.