"The angle makes the difference," finished Hiller. "If we entered the belt at about this angle"--he inclined the ballpoint up slightly from the horizontal--"we'd sail through with the same velocity as the particles. If we hit any, it would be a nudge from our transit motion through the Belt or from their velocity or revolution, which is probably very low." "I get it," Merrick slapped his forehead. "Our present course cuts the Belt at such an angle that we get bumped at two m.p.s. instead of 12." The others nodded. He reflected a moment, adding, "So, I get a bullet through the head at 1200 feet per second or 200 feet per second: I still get it in the end." "Not in this case," Hiller smiled. "There's been quite a little work done on effects of meteor impact by the Air Force. I've got a summary of it in the control room. Art, here, could probably tell you more about it than I could." * * * * * Eastburn hugged his knees. "Not much, I don't think," he arched an eyebrow. "Fred's being modest, the guy who designed the meteor-scanning device used on all Marships. I'll take the ball, though, on this one. "Del, we've got a brute of a hull on this ship, twice as resistant as the ones on I and II. Second, it's smooth and curved. Third, it's going awfully fast. The studies the Air Force has been able to make so far show that small-sized meteors either glance off a ship and disintegrate swiftly from the excessive rotation set up from the collision, or they explode on contact from built-up kinetic energy. "There seems to be three types of contact explosion. Where the angle of impact is not quite perpendicular, the particle creases the hull and explodes along its trajectory. This is the usual situation in the heat-generation collision and rarely harms the ship. "Perpendicular impact, however, does the damage. At low velocities and densities perpendicular impact craters the hull and most of the blast effect is dispersed laterally and to the rear. At higher velocities the particle vaporizes but the explosive force craters the hull and shapes inward, a lot like the effect of an air gun pellet on plate glass. Although the hull penetration may be mere pea size, blast and compression inside can be terrific, besides the sharp shock throughout the whole ship." Hiller grinned. "Thanks for bringing out the situation so well, Art. Hollender's the mathematician here, and I don't go in for formulating odds. But I'll give odds right now on our getting through with one perpendicular strike. Any takers?" "That's a hell of a bet," Merrick griped. "If you lose, who's around to collect?" "I'm talking odds," the commander said. "Anyway, you over-estimate the effect of a perpendicular strike. In a closed compartment it could be rough. By leaving every compartment hatch open, the compression would dissipate throughout the ship with less damage."