They began to feel the gravitational attraction of the miniature world, and they had to bolster rocket fire to combat it. Unlike Venus, Mercury could not be avoided in this flight.

Steve watched the gauges, especially the refrigerator dial. The latter was holding up well under this maximum barrage of heat from Sol, but there was still an oppressive hotness that reached through the laboring artificial coolness and penetrated Steve’s pores like insidious rays.

“If the Comet isn’t superior to Dennis’s in any other way, it’s made of better heat-resistant alloy,” Bart had said with self-assurance before leaving Earth. Steve wondered now if the proof of this assertion would be settled before both ships were beyond the sun’s reach.

Hours later, when the Condon Comet had passed Mercury, Steve was impelled to check on their rivals behind. For a moment he couldn’t find the ship on the TV screen. When he spotted it at last, by changing the direction of the movable screen, he was amazed to find the craft far below, hovering over the planet.

“Bart!” Steve called. “It looks as if Jim and Pete are in trouble! They’re diving for Mercury and seem to be heading for the terminator line between the dark half and the light!”

Steve wished there were some kind of radio communication between the ships, but electrical interference from the sun made radio impossible on these round-the-sun races.

“We’ve got to go down there, Bart,” Steve said.

“We haven’t won yet, Steve. There’s still the record to beat.”

“Will you stop thinking about records!” Steve retorted. “There are a couple of men down there in trouble!”

“Did they stop for us?” Bart bit out. “It’s probably only a trick to lure us down so that Dennis can make a quick getaway!”