Slowly one board was lifted and pushed aside and a second followed.

Then two heads appeared in the gloom.

"Robbers!" cried Snap.

"Burglars!" yelled the doctor"s son.

"Shoot them!"

"Don"t let them get away alive!"

Then with a vigorous throw Snap landed his pail of stuff full upon the head of Ham Spink. Splosh! it struck the dudish youth squarely in the face and ear. Another splosh followed, and Carl Dudder was likewise decorated.

"Hi! wow!" spluttered Ham. "I---Oh, what a smell!

"Oh, my eye!" groaned Carl. "Phew! what"s this?"

"We"re discovered!

"What"s this they threw on us?"

"Oh, did you ever smell such stuff?"

"Robbers! thieves!" yelled Snap and Shep. "Shoot them! Give them a dose of buckshot!"

"They are going to shoot us!" screamed Carl Dudder, and dodged down. Then he lost his footing on the wet and slippery rails, clutched at Ham to save himself, and both went down with a loud splash into the dirty water under the boathouse.

"There they go!" cried Shep.

"Let us scare them some more," whispered Snap. "Pretend you don"t recognize them."

Quickly a lantern was lit and held over the opening in the floor.

Down below two dark forms, covered with mud and flour paste, could be seen clutching at the slippery braces of the spiling. Snap and Shep could scarcely keep from roaring.

"There they are! Get the gun!" yelled the doctor"s son.

"Two dangerous burglars!" cried Snap. "Wonder where they came from?"

"W---we ar---are not burglars!" spluttered Carl. "We are---"

"Do---don"t sh---shoot!" wailed Ham Spink. "We di---didn"t mean---"

Bang! went the shotgun Snap had picked up. He fired at the corner of the building, into a ma.s.s of rubbish. A piercing yell of terror came up from below, and down dropped Ham and Carl into the water once more. They were too afraid to come up under the boathouse again and so struck out for the river bank some distance away.

"They are going away!" called out Shep. "They are two desperate burglars! Give them another shot!"

"Perhaps they have been robbing some stores," called out Snap.

Then he discharged the shotgun once more, and down ducked Ham and Carl again, yelling wildly in their fright. They swam with energy and soon reached the shelter of another boathouse. Here they crawled from the water and took to their legs with all the speed at their command. Both were frightened nearly out of their wits, and for the time being paid no attention to the foul-smelling paste and mud that covered them.

"They---they thought we were thi---thieves!" panted Carl, after he and his crony had covered several blocks.

"Yes, and we came near being shot dead!" added Ham.

"I didn"t know they were going to stay there to-night."

"Neither did I."

"Those shots will wake up the whole town."

"Yes, and we must get out of sight. Phew! what a smell!"

"They dumped something down on us."

"Must have been rotten eggs. What are we going to do?"

"I don"t know---go home, I guess."

"I can"t go home looking this way."

"You"ll have to go."

"Well, it"s lucky they didn"t recognize us."

"That"s true. But this suit is about ruined."

"So is mine. And we didn"t hurt their outfit at all."

"Never mind, we"ll get square with them another time."

After that Carl and Ham separated and each lost no time in sneaking home and washing up and trying to clean his garments. They did not dare to tell their parents of what had occurred and so had to suffer in silence.

The shots from the gun aroused some folks living near the river front, and several men came down to the boathouse to learn what was the matter.

"Two fellows tried to get in here, but we scared them away," said Snap.

"Who were they?" asked one man.

"Two fellows dressed in dark suits and with slouch hats."

"Did you hit them?"

"No, we only fired to scare them off."

"Where did they go?"

"Ran back of d.i.c.kson"s boathouse," answered the doctor"s son.

A brief search was made, but the prowlers, of course, were not located. Then the men went home, and Snap and Shep settled down to make themselves comfortable for the rest of the night.

"Ham and Carl won"t forget that reception in a hurry," remarked the doctor"s son, and indulged in a laugh, in which his chum joined.