Chapter V. A Clew from Russia

"Nothing much up here," remarked Tom, when he and Ned had gone all over the second floor twice. "That scrap of paper, which put me on to the fact that some one from the Russian government had been here, is about all. They must have taken all the documents Mr. Petrofsky had."

"Maybe he didn't have any," suggested Ned.

"If he was wise he'd get rid of them when he knew he was being shadowed, as he told us. Perhaps that was why they broke up the furniture, searching for hidden papers, or they may have done it out of spite because they didn't find anything. But we might as well go downstairs and look there."

But the first floor was equally unproductive of clews, save those already noted, which showed, at least so Tom believed, that Mr. Petrofsky had been surprised and overpowered while at breakfast.

"Now for outside!" cried the young inventor. "We'll see if we can figure out how they got him away."

There were plenty of marks in the soft ground and turf, which was still damp from the night's rain, though it was now afternoon. Unfortunately, however, in approaching the house after leaving the aeroplane, Ned and Tom had not thought to exercise caution, and, not suspecting anything wrong, they had stepped on a number of footprints left by the kidnappers.

But for all that, they saw enough to convince them that several men had been at the lonely house, for there were many marks of shoes. It was out of the question, however, to tell which were those of Mr. Petrofsky and which those of his captors.

"They might have carried him out to a carriage they had in waiting," suggested Ned. "Let's go out to the front gate and look in the road. They hardly would bring the carriage up to the door."

"Good idea," commented Tom, and they hurried to the main thoroughfare that passed the Russian's house.

"Here they are!" cried Ned, Who was in the lead. "There's been a carriage here as sure as you're a foot high. and it's a rubber-tired one too."

"GOOD!" cried Tom admiringly. "You're coming right along in your detective training. How do you make that out?"

"See here, where a piece of rubber has been broken or cut out of the tire. It makes a peculiar mark in the dirt every time the wheel goes around."

"That's right, and it will be a good thing to trace the carriage by. Come on, we'll keep right after it."

"Hold on a bit," suggested Ned, who, though not so quick as Tom Swift, frequently produced good results by his very slowness. "Are you going off and leave the airship here for some one to walk off with?"

"Guess they wouldn't take it far," replied the young inventor, "but I'd better make it safe. I'll disconnect it so they can't start it,