"Penetrative power is not the sole requisite of a felling axe; for if the edge be too thin, it will be found much easier to drive it into the wood than to pull it out again; for this reason, narrow felling axes are left with a thick obtuse edge, so as to avoid penetrating too deep into the wood. A narrow axe may cut a larger section of wood than a broad one the cutting edges being equally thick; that is, the fall of a narrow axe may more than make up in depth of cut what it wants in breadth of a broader one. But it seems a waste of power to force the obtuse edge of a narrow axe through the wood, when the same power would make a broader one, with a more acute cutting edge, penetrate equally far, and thus cut a larger section. It would appear, then, that as deep cutting can be avoided by adding either to the breadth or the thickness of the edge; and that as the broad edge will cut a larger section than the thick one, that the edge ought be as thin as consistent with strength, and sufficiently broad to prevent it sticking in the wood; so that the conclusion arrived at in this case is, that the American or broad shaped felling axe ought to yield a greater quantity of work than the long felling axe, with the same amount of labour."
~Daniel Doull, The Manipulation of Wood and the Forms of Edge Tools Used Therein, The Irish Industrial Magazine - Volume 1 - Page 477, 1866
