Gang saw, 30 square feet of dry oak, or 45 square feet of dry pine, per hour........................... 1 horse-power.

Circular saw, 2.5 feet in diameter, 270 revolutions per minute, 40 square feet of oak, or 70 of dry spruce.................................................... 1 "

300 revolutions per minute. 1.33 square feet of dry pine per minute, kerf 7/32 inch and 6 inches deep, requires the power of 1 horse for the saw alone; and 1 square foot, kerf ¼ inch and 1 foot in depth, requires a like power.

4.5 feet in diameter, kerf \ and 1 foot in depth, requires 1 horse's power for 1.33 feet per minute.

Oak requires nearly one-half more power than pine.

With a kerf of 1/8 inch, 1 horse's power will saw 2-66 square feet per minute.

The speed of the periphery should be about 50 feet per minute.

Velocities of Wood-working Machinery in Feet or Revolutions per Minute.

Circular saws, at periphery, 6000 to 7000 feet.

Band saw, 2500 feet.

Gang saws, 20 inch stroke, 120 strokes per minute.

Scroll saws, 300 strokes per minute.

Planing-machine cutters at periphery, 4000 to 6000 feet.

Work under planing-machine, 1/20th of an inch for each cut.

Moulding-machine cutters, 3500 to 4000 feet.

Squaring-up-machine cutters, 7000 to 8000 feet.

Wood-carving drills, 5000 revolutions.

Machine augers, 1½ diameter, 900 revolutions.

Machine augers, ¾ diameter, 1200 revolutions.

Gang saws require for 45 superficial feet of pine per hour, 1 horse power.

Circular saws require for 75 superficial feet of pine per hour, 1 horse power.

In oak or hard wood, ¾ths of the above quantity require 1 horse power.

Sharpening Angles of Machine Cutters.

Adzing soft wood across the grain........................... 30°

Planing-machines, ordinary soft wood..................... 35°

Gouges and ploughing machines........................... 40°

Hard-wood tool cutters 50° to 55°