This maneuver was accomplished without a hitch, and Bob was soon safely on the raft. Out that far on the lake the air was a little cooler, so that it was possible to work without being scorched. Once aboard, Bob helped Joe to clamber on, and then they fell to work like madmen, stripping wires and making connections. The batteries they connected in series, thus doubling their voltage, and then connected them to the primary coil of their inductance unit. Fortunately the latter was an unusually large and powerful one, and the induced voltage in the secondary was very heavy. Owing to the high resistance of the secondary the amperage was necessarily low, but when the primary circuit was made and then suddenly broken the induced voltage in the secondary was of such strength as to give a paralyzing shock to any object with which it might come in contact. One side of the secondary was grounded to the water, and then their impromptu shock-giving apparatus was ready for use.
And not a minute too soon. The bears, five in number, had been circling about the raft, somewhat doubtful about its nature, but without doubt desperate enough to rush at it as soon as they became familiar enough with it. Bob had hardly made the last connection when Jimmy uttered a warning cry.
“They’re coming, Bob!” he yelled. “All five of them at once!”
CHAPTER XXII
FIGHTING OFF THE BEARS
Jimmy’s warning came not a moment too soon, for the words were hardly out of his mouth before two of the bears came splashing toward the raft. Buck Looker gave a yell of terror and started swimming away as fast as he could. Jimmy and Herb had to let go, too, and swim out of the reach of those big paws that were propelling the bears forward at surprising speed. The largest one was soon close to the raft, and Bob could see one big paw lifted in preparation to climb aboard.
With one hand Bob depressed the key that completed the circuit through the primary coil and held the end of the high tension lead, which he had lashed to a long stick, close to the bear’s moist black nose. Then he released the key.
With a hiss and a snap a long blue spark crackled between the terminal and the bear’s nose. Bob worked the key rapidly up and down, and at each break another high voltage spark jumped to the animal’s sensitive snout. Each spark had the force and effect of a heavy hammer blow, and the bear half roared and half squealed in pain and fright. One big paw came up and tried to brush away that agonizing, stunning thing, but this only transferred the sparks to his paw. With a terrified squeal he turned about and swam off at top speed. The other bear was puzzled at the behavior of his companion, but he could see no reason why he should not get up on the raft, even though the other, for some incomprehensible reason, had failed. Accordingly he made a rush, but was even less fortunate than his predecessor, for by now Joe had gotten his outfit to working properly, and the animal had to face two streams of sparks instead of one. They tore through him with paralyzing force, and he slipped back into the water, hardly able even to swim.
Meanwhile the other three bears had been swimming about the raft, growling and grunting. The fate of their two companions made them suspicious and puzzled them, but at last they seemed to muster up courage all at the same time, and as though through a preconcerted signal they charged down on the raft at once. For a few minutes it was nip and tuck, and it looked as though the bears might win by sheer weight of numbers. One actually dragged himself half way up on the raft, tilting it at such an angle that it was all Bob and Joe could do to keep their footing. Once Joe’s stick was knocked out of his hand, and Bob had to stand off all three until he could recover it. Herb and Jimmy swam about, almost crazy with the desire to help their hard-pressed comrades, but of course unarmed as they were, there was nothing that they could do. Indeed, they were taking big risks by remaining close to the raft, for there was no telling when one of the bears, infuriated by the baffling electric discharges, would attack one of them by way of venting its fury. Luckily, however, the animals were so dazed and frightened by the novel defense put up by these strange beings on the raft that there was little fight left in them, and their only thought was to get away from that stinging, hammering torment as soon as possible. With grunts and squeals they turned tail to the raft, their going accelerated by a string of writhing blue sparks that hissed and snapped after them as long as Bob and Joe could reach them with their long poles.
The discomfiture of the big brutes was so sudden and complete that the boys were actually surprised at their own success. But the victory had not been won so easily as they had supposed. The bears, it is true, had been driven off, but they had gone no great distance when they stopped and began circling about the raft, growling fiercely and evidently meditating a further attack.
“If they all come on at once, we’d better all be on the raft to ward them off,” said Bob. “We can rig up two more electrodes, and we may need them all before we get through.”