Hal had his head up through the hole so that he could carry on this conversation with his brother. Suddenly he dropped down as he saw the swordfish coming straight for the jeep. He raised the electro-gun and was about to fire when the swordfish, with a powerful flick of its tail, shot again out of range.
They had already waited two hours; now they waited another hour before Hal could deliver the final blow. The sharp hypodermic did its work and the swordfish lay still.
‘But it seems cruel just the same,’ Roger said.
‘Any killing is cruel,’ said Hal. ‘You and I prefer to take animals alive. But remember, just now we are not trying to get animals for a zoo. We are trying to find better ways to get food for people. And you can’t get meat without killing. This way of doing it didn’t hurt the fish one bit Don’t you think it was a lot better than stabbing the fish with a big hook in its mouth and torturing it for several hours before you can pull it aboard?’
He slipped out with a net which he threw over the swordfish and looped the rope around Bottle’s neck. The eager dolphin shot up towards the ship, easily towing the big fish. Hal phoned Captain Ted to stand ready to haul the fish aboard.
But the young naturalist was disappointed with his experiment. He considered that it was a failure. It had taken three hours to get one fish. Such a slow procedure would never feed the world’s hungry millions.
But there was the laser. It was something quite new. He had never used it before. He examined the instrument. It was about the size of a cine-camera.
Roger said, ‘Is this all there is to it? I don’t see any harpoon or gun or anything.’
‘Yes,’ Hal said. ‘This is all there is to it. But it’s a pretty wonderful thing. That electro-gun isn’t much good unless what you’re shooting at is not more than thirty feet away. This will reach a hundred thousand miles.’
Roger was incredulous. ‘You’re putting me on.’
‘No, I’m not. Astronauts half-way to the moon could use it to talk to the earth. It sends out a beam of light and a voice can go along on the beam.’
‘I’ll bet anything that could do that will be terribly expensive.’
The first ones were. But an I.B.M. research man, Dr Peter Sorokin, has invented this cheap model. I bought this for only fifty dollars.’
what use is it to you? Do you want to talk to the fish?’
‘No, but I want to find them. This should help me find them. It works like an echo sounder, only better. It will not only find a big fish, but tell me how far away it is.’
‘You mean, it talks?’
‘Not exactly. It clicks. Listen.’ He turned on the machine and a ray of light shot forth. At the same time the thing began to click. There was quite a long pause after every click.
‘That click goes out along the beam,’ Hal said, ‘and if it strikes a large object like a big fish, the echo will come back. And the length of time it takes the echo to come will give us an idea of how far away the fish is. Now, let’s go hunting.’
He slowly turned the eye of the machine and the beam began to travel to the right. The clicking continued but for a while there was no answer.
Then suddenly there was an echoing click.
‘There’s our fish,’ said Hal excitedly. ‘Must be a big one, because it’s a strong echo. The larger the fish the better the echo. According to this dial it must be about two miles away.’
‘But what good is that?’ Roger objected. ‘By the time we get there it will be gone.’
‘We don’t go to it,’ Hal said. ‘It will come to us.’
Roger stared at him. ‘What would make it come to us?’
Hal turned a dial and the clicks became very rapid and strong. ‘A hundred clicks a second,’ Hal said. ‘And carried along by the beam, they strike the fish very hard. Fish have a lot of curiosity. When they hear an unusual sound they come to see what is making it.’
‘I know that,’ Roger said. ‘When we went shark-hunting in the islands we rapped on the side of the boat to attract the shark. It came to see what was making all the noise and when it got within a few feet of the boat we would give it the harpoon.’
‘Yes,’ Hal said, ‘and this big fellow is coming fast. The dial shows he has covered a mile in the last few minutes. I’m going to get out with the electro-gun and be ready to give him a warm reception when he arrives. Do you think you can operate this thing? Wait until I get this fish - then immediately turn the beam until you get another echo.’
‘Sure, I can do that,’ Roger said, proud to have a part in this strange experiment.
Hal dropped into the sea, gun in hand. In an amazingly short time something that looked like a zebra but was twice as large came charging down the light beam. It was more colourful than the zebra. Its stripes were lavender against a silver background, its fins were deep blue, its back was green and belly white. Hal recognized the famous striped marlin. A record specimen that had been taken by Zane Grey off Tahiti weighed one thousand and forty pounds. But nearly all fish of the Great Barrier Reef were larger than those of Tahiti waters and this one was a true monster.
It did not act like the swordfish which had dillydallied around for an hour before it came close enough to be shot. This fellow could not wait to investigate that clicking sound. It came straight to the jeep and did not stop until its bill touched the glass. Hal fired. The electric shock acted instantly and painlessly.
The end of the coil of rope that Hal carried over his shoulder was slipped into the open mouth and out through the gill, then made fast to one of the jet pipes of the jeep.
Roger had already turned the beam and located another echo. This time the distance was much less and it was not two minutes before another big visitor appeared, this time a silver marlin of somewhat smaller size, no heavier than a horse, about five hundred pounds.
Hal easily bagged it, slipped the same rope through mouth and gills and left it beside its cousin.
He had hardly finished before another marlin hove in sight - evidently this was to be marlin day. This one was the famous Pacific black marlin. The record catch of black marlin weighed one thousand two hundred and twenty-six pounds and was caught in these same waters by a sportsman who struggled most of the day to haul it in.
Any fisherman with rod and line would be very lucky to get one marlin in a day, and it would more likely take a week. And laser had brought in three in ten minutes.
The next was also a black marlin that looked as big as an elephant. It was followed almost at once by a huge grouper with goggle eyes and heavy jaws, an astonished look, and mouth opening and closing that seemed to be saying, ‘Oh, brother!’
The laser was working well. It picked up only fish that sent back a strong echo, and that meant a big fish every time.
After six more takes. Hal signalled Roger to turn off the beam.
He slipped the rope off the jet and noosed it around the neck of Big Boy in spite of eager whistles from the dolphins who wanted to get in on the game. But this was bo job for a dolphin. It took a monster to haul these monsters to the surface.
It was hard work even for the powerful killer whale. He knew where he was supposed to go but found the load almost beyond his strength. Slowly he swam upwards. Hal returned to the jeep. He phoned Captain Ted and told him what to expect.
But even with this warning the captain was not prepared for what he saw when Big Boy broke the surface beside the ship with his cargo of monsters. Captain Ted phoned Hal.
‘What sort of a joke is this? How do you think I’m going to get these elephants aboard?’
‘Use your crane,’ Hal suggested. Take up one at a time.’
‘But where will I put them? The tanks aren’t big enough.’
‘Stow them in the hold,’ Hal said. ‘And be ready to take on a lot more.’
Hal could hear a deep sigh from the other end of the line. ‘Fifty years at sea,’ moaned Captain Ted, ‘and I’ve never seen anything like this.’
But he was to see a lot more. Withi
n an hour a distress call came down from above. ‘Let up, will you? The hold is chock full and every inch of the deck is taken. We’re walking around on fish. We’re going to sink if we take on any more of these brutes.’
Hal laughed. ‘Okay. Take them to Cairns and deliver them. Use both sails and engine and make a quick trip of it. We’ll wait, and have a lot more for you when you get back.’
Captain Ted groaned and rang off.
‘What do you mean, more?’ Roger complained. ‘Don’t you think we’ve done enough for today?’
Hal smiled. ‘We’ve done enough to prove that the laser and electric gun work well together. Any fishing smack can afford to buy a laser. But perhaps it won’t be equipped with the electric shock apparatus. I want to see if the laser alone will do the trick.’
Roger looked puzzled. ‘The laser pulls them in all right. But it doesn’t kill them.’
‘I think perhaps it will if we turn up the power,’ Hal said. ‘In medicine, laser is used to cure some diseases. For instance, there’s a very bad tumour, something like cancer. It’s called melanoma. At the Pasadena Tumor Institute they use laser to kill melanoma. It takes only a very weak beam and only a thousandth of a second.’
‘What does curing that thingamajig have to do with killing fish?’
“The reason for using a weak beam is that a strong one would kill both the tumour and the patient. We’ve been using a very weak beam to bring in these fish. But suppose when the fish arrives we suddenly turn on the strong beam. Of course these big chaps are much more powerful than a human and they may be able to stand the shock. I don’t know - that’s what we’ll find out.’
They soon found out. The low-power beam brought in the fish. At the last moment when the inquisitive fish nosed the jeep the laser was switched to high-power and the fish, without knowing what had struck it, passed out.
Long before Captain Ted telephoned that he had come back from the twenty-mile trip to Cairns, there was another big load waiting to go aboard.
This time neither the dolphins nor the killer whale were to have the fun of towing the catch to the surface.
‘Break out the balloons,’ Hal said. ‘I think we’ll need three,’
‘What are the balloons for?’
To do the same job that the dolphins and Big Boy were doing.’
‘But if they can do it, why use balloons?’
‘We have to think of all the possibilities,’ Hal said. ‘Let’s suppose you are the captain of a fishing smack. You may be able to train dolphins to help you, or you may not. Or perhaps there are no dolphins in the seas where you are working. Your divers round up the fish by laser, but how are you going to get them up to the ship?’
‘I see,’ said Roger. ‘But you can’t use balloons for that. They work only in the air.’
‘What makes you think so?’
‘Because I’ve seen them in the air, but never underwater.’
‘But why won’t they work underwater? They work in the air because we fill them with gas that is lighter than air. They should work underwater if we fill them with gas that is lighter than water.’
‘What gas?’
‘Any gas. Air itself is a gas, and it’s a lot lighter than water.’
He took up the bottle of compressed air that Captain Ted had sent down. “This is air under great pressure and it will expand enough to fill three balloons. I’ll go out, and you can hand me the balloons one at a time.’
Hal went under and Roger passed him the first balloon. Hal roped together about a dozen of the big fish and made fast the rope to the balloon. Then he latched the air bottle to the balloon nozzle and turned on the valve.
The balloon filled at once and lifted so powerfully that Hal could no longer hold it. Up it went, towing the heavy load.
Hal returned to the jeep. ‘Phone the captain,’ he said. ‘And pass me another balloon.’
Another haul of fish went up with the second balloon, and the final lot with the third. Altogether, the boys had taken several hundred groupers, barracudas, wahoos, cobias, giant mullets, dorados, and albacores - all good foodfish.
The distressed voice of Captain Ted came over the radiophone. ‘You’re driving us wild. What do we do with all these?’
‘Take them in to the packing plant,’ Hal said. ‘They’ll know what to do with them.’
What the city of Cairns could not use could be shipped by train to the towns of the Australian coast all the way from Cape York at the northern tip to Melbourne in the south. Or they could be canned to go to India or any other part of the hungry world.
The important thing was not this great haul of fishes, but the fact that ways had been opened up for the fishing industry everywhere to increase its output perhaps a hundredfold. But only if fishing captains everywhere knew of the success of these experiments. Hal knew that Dr Dick would eagerly take care of that by his reports to scientific journals and journals of the fishing industry.
That was up to Dr Dick. The boys were already impatient to get on to something else.
‘What’ll we do now?’ demanded Roger.
‘Well,’ said Hal, looking out at several Writhing, twisting, evil-looking things close to the jeep, ‘if you don’t mind doing something a bit more dangerous, let’s go play with snakes.’
Chapter 11
Sea snakes
Roger was not bubbling with enthusiasm over the idea of playing with snakes.
‘They don’t look like good playmates,’ he said. ‘But I suppose they can’t really do any harm.’
‘I don’t know why you suppose that,’ said Hal. ‘Of course there are many kinds of sea snakes and some of them just swim away. But the ones along the Great Barrier Reef are not so meek and mild. They are big - those outside seem to be about ten feet long. And they would as soon bite you as not. They are supposed to have the same ancestor as the cobra and krait. The venom of one species is fifty times as strong as the king cobra’s.’
‘Then why do you want to fool with them?’
‘Because one of the most important things we have to do is to collect poisonous animals for laboratories.’
‘What can they do with them?’
‘Extract the poison. You know how they milk a snake to get the venom. Then they use the venom to make anti-venin to cure snakebite. But they also use all sorts of poisons from snakes, fish, jellyfish, sea wasps, and many other sea creatures to make medicines good for all sorts of diseases. So far as I know, no such collection of venomous animals has been made in the waters of the Great Barrier Reef.’
Roger understood. ‘I get you,’ he said. ‘Let’s go. How do we kill them?’
‘We don’t kill them. We take them alive. If we kill them the poison would spoil before we could get them to the labs.’
Roger looked closely at the sea snakes. ‘You say their grand-daddies were cobras. They don’t look much like cobras to me. See how broad and flat their tails are. Besides, how could they be descended from cobras? The cobra is a land snake.’
‘So were these - once. They used to live on land. Then, for some reason they took a fancy to go to sea.’
‘How do you know that?’
‘We know it because they have lungs, not gills. They breathe air. They can stay down for a long time, even for hours, but then they must come up to breathe.’
‘But,’ objected Roger, ‘no land snakes have broad tails like those. How do you explain that?’
‘Well,’ Hal said, ‘think of the dolphins. They once walked around on land. But when they came to the sea their feet gradually changed into fins and their tails became wide and flat so they could push themselves through the water. The tails of those snakes are now powerful paddles that can shoot them through the water at tremendous speed.’
Now there were more snakes than ever. Some were darting at the jeep as if trying to get at the luscious morsels inside. Their fangs thudded against the glass.
‘Come to think of it,’ Hal said, ‘I believe you had better stay inside.’
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Roger screwed up his courage enough to say, ‘Not on your life. If you can take it, so can I.’ He was done with being considered the baby of the family. He was big for his age and almost as strong as his brother.
‘All right,’ Hal said reluctantly, ‘but you know how to take a snake?’
“Sure. You grab it behind the head.’
‘And hang on,’ Hal added. ‘They’re strong. They’ll twist away from you and bite if they can.’
‘Enough instructions,’ Roger said. ‘Let’s get going.’
They slid out through the hatch. The snakes scattered. Probably they had never known sea monsters like these and were a little afraid of them. But they were very curious. Or hungry. They would attack other sea animals of all sizes, so why not these?
They swam about with their jaws open. Their hollow, poison-filled fangs did not lie down like the fangs of some snakes, but stood erect like those of the cobra. Their forked tongues darted in and out.
They were really a gorgeous sight, evidently of several different varieties. Some were yellow-bellied, some a dazzling blue, some brown with yellow bands or yellow with black bands. Both boys had seen enough snakes in their father’s zoo to appreciate their beauty and they had taken snakes alive in Africa, but never before beneath the sea. These creatures were so much at home underwater and glided about with such ease that the boys who had not spent millions of years beneath the waves felt clumsy and out of place. These were their air-breathing cousins - but cousins far removed.
They swarmed around the boys, staring at them with big beady eyes. Why was their stare so menacing? Roger decided it was because they never blinked their eyelids. Then he saw that there was good reason why they never blinked - they had no eyelids. And they had no ear openings. They heard (or rather felt) with their tongues. Those darting tongues looked dangerous. But Roger knew that even the tongue of a poisonous snake is quite harmless. The tongue is used to detect sounds, just as the nerves in the lateral line down the side of a fish are sensitive to any sound.
11 Diving Adventure Page 6
