604 THE USE OF FLINT BLADES TO WORK PINE WOOD. 
on a piece of iron which made it bound, and caused a small fragment 
(0.03 meter long and 0.003 meter thick to fly off one of the corners 
without diminishing the sharpness of the axe. 
These three experiments were made with the same blade, 0.075 
meter long, of gray flint, of which the edge, a little concave, was 
0.065 meter in width. At one of the corners of this some chips were 
wanting, having been broken off before the experiment. It was other- 
wise in a good condition, and very sharp, only having serrations here 
and there. The shorter of the beveled faces is a little curved and 
this made the blade slightly convex. The scarfs produced by the cut- 
ting were perfectly regular and exact, and the surface, left by the 
removal of the chips would have been also quite smooth if the serra- 
tions of the edge had not left some inequalities. 
IV. In striking some blows on a pine pole, dry and not planed, 0.03 
meter thickness, | have proved that the same blade would quite as 
well cut harder wood. 
It would have been naturally much easier to fell a sapling standing 
than to cut the blocks fixed on a stand, for the wood yielded in a man- 
ner to compress the fibers in one way and expand them in the other; 
the blows penetrated better in the latter case. 
V. A log of pine 0.13 meter in diameter, fixed on a table, was cut in 
eight minutes with the ax. It is a blade of gray flint 0.07 meter long, 
of which the convex and uneven edge is 0.0675 meter wide. Before the 
experiment the edge was a little damaged in the middle and did not 
work as well. The chips were short and the incisions uneven. The 
part separated from the log which was pointed with the ax used in the 
first three experiments, shows the surfaces equal and nearly polished. 
VI. One of the logs had the knots which I had sueceeded in avoid- 
ing in the preceding experiments. With a blade whose edge was 
extraordinarily straight and regular, but a little thick (the bevelled 
parts show an angle of inclination of 45°), I cut with the greatest 
ease these knots, of which the largest was 0.03 meter in diameter, 
without any marks thereof appearing on the edge. The thickness 
of this ax, on the contrary, makes it cut with less facility into 
wood soft and without knots. To ascertain the limits of resistance in 
this blade, I struck with all my force, almost perpendicularly, a large 
knot remaining on a branch cut on the stump. The branch was stand- 
ing horizontally. The edge penetrated in the knot 0.01 meter, but the 
same time the ax split, and the thick fragment broke off about a third 
of the edge and all the narrow face of the ax, which came off from the 
head. 
VII. The experiment showed to me that the little blades could per- 
fectly take the place of chisels. 
VIII. With the same instruments used as chisels I shaped two logs 
to mortise and tenon. All the logs of the experiment were still covered 
with bark. 
