“Forgive me for contradicting you,” smiled Vance; “but yesterday morning I questioned Captain Hagedorn at some length, and learned that there had been no deflection of the bullet. Hagedorn had inspected the wound before we arrived; and he was really pos’tive on that point. In the first place, the bullet struck the frontal bone at such an angle as to make deflection practically impossible even had the pistol been of smaller calibre. And in the second place, the pistol with which Benson was shot was of so large a bore—a point-forty-five—and the muzzle velocity was so great, that the bullet would have taken a straight course even had it been held at a greater distance from the gentleman’s brow.”
“And how,” asked Markham, “did Hagedorn know what the muzzle velocity was?”
“I was inquis’tive on that point myself,” answered Vance; “and he explained that the size and character of the bullet and the expelled shell told him the whole tale. That’s how he knew the gun was an army Colt automatic—I believe he called it a U. S. Government Colt—and not the ordinary Colt automatic. The weight of the bullets of these two pistols is slightly different: the ordinary Colt bullet weighs 200 grains, whereas the army Colt bullet weighs 230 grains. Hagedorn, having a hypersensitive tactile sense, was able, I presume, to distinguish the diff’rence at once, though I didn’t go into his physiological gifts with him,—my reticent nature, you understand. . . . However, he could tell it was a forty-five army Colt automatic bullet; and knowing this, he knew that the muzzle velocity was 809 feet, and that the striking energy was 329—which gives a six-inch penetration in white pine at a distance of twenty-five yards. . . . An amazin’ creature, this Hagedorn. Imagine having one’s head full of such entrancing information! The old mysteries of why a man should take up the bass-fiddle as a life work and where all the pins go, are babes’ conundrums compared with the one of why a human being should devote his years to the idiosyncrasies of bullets.”
“The subject is not exactly an enthralling one,” said Markham wearily; “so, for the sake of argument, let us admit that you have now found the precise point of the gun’s explosion. Where do we go from there?”
“While I hold the string on a straight line,” directed Vance, “be good enough to measure the exact distance from the floor to the knot. Then my secret will be known.”
“This game doesn’t enthrall me, either,” Markham protested. “I’d much prefer ‘London Bridge’.”
Nevertheless he made the measurement.
“Four feet, eight and a half inches,” he announced indifferently.
Vance laid a cigarette on the rug at a point directly beneath the knot.
“We now know the exact height at which the pistol was held when it was fired. . . . You grasp the process by which this conclusion was reached, I’m sure.”