spinning and skidding uncontrollably over the water as the propulsion unit reinforced the spin set up by the two lateral jets. The others burst at random without effect and a moment later the vehicle came to rest, still spinning slowly, with its topside breaking the surface.
One of the Melfans retrieved it and a technical argument started regarding the inherent instability of the flattened ovoid configuration. Gurronsevas was too angry and disappointed to join in, but not so Murchison.
“This is not my specialty,” said the pathologist, “but when I used to play with my big brother’s toy boats as a child, they were fitted with keels which gave them directional stability even when the wind changed. When we grew older and progressed to speedboats and submarines we had radio-controlled rudders and diving vanes to maintain or change direction or depth. Couldn’t something similar be used here?”
Timmins and the Melfans stopped talking but did not reply. They were all looking at Gurronsevas. Plainly he could remain silent no longer.
“No,” he said. “Not unless the radio receiver and actuating devices could be fabricated from materials that were non-metallic, non-toxic and edible.”
“
“In its final form,” said Gurronsevas, doing so, “the entire vehicle would have to be edible, or at least non- toxic to the Chalder life-form, and that would include the water-soluble gas containers for propulsion and steering. The problem with the addition of a keel, which would also have to be edible and not sharp-edged enough to risk injury to the patient’s mouth, is that the structure would change the visual appearance of the vehicle so that it no longer resembled the Chalders’ natural and greatly preferred food source, which is a streamlined, hard-shelled, aquatic animal of the size and configuration of our test object. A weak and convalescent Chalder patient might not consider it worth the effort to chase unfamiliar food.
“You will understand,” Gurronsevas continued, “that the confined space of the AUGL ward causes physical as well as physiological effects which unnecessarily lengthen the period of convalescence. The patients become lazy, listless, almost debilitated by their inability to exercise properly. I should explain that the physiology of the AUGLs is such that—”
“I am familiar with the physiology of the Chalders, among others,” said Murchison.
For a moment Gurronsevas radiated embarrassment so strongly that he was surprised the water around him did not steam. He said, “My apologies, Pathologist Murchison. This Chalder knowledge is very new to me, and very exciting, and in my excitement I stupidly assumed a similar level of ignorance in others. I had no wish to offend you.”
“You didn’t,” said the pathologist. “I was just trying to stop your wasting time on an unnecessary explanation. But I have no knowledge or professional interest in the non-intelligent life-forms on Chalderescol, including the food animal you are trying to copy. How does the real one propel itself and take evasive action and manage to retain directional stability?”
Feeling greatly relieved, Gurronsevas said quickly, “On each side the animal has a set of eight laterally- mounted paddles. Their frequency of beat and angle of attack against the water can be varied so as to make the animal rise, dive, or — by going into reverse beat on one side — make a sudden change in direction. The paddle structure is a translucent framework supporting a transparent membrane which, when the creature is fleeing, is beating so fast as to be virtually invisible. When there is a change in direction, minor turbulence is created which is visually similar to the bubbles produced by the test object’s attitude jets.
“Regrettably,” he added, “the model looks but does not behave like the real thing. It is hopelessly unstable.”
“That it is,” said Murchison. For several minutes it remained silent, staring thoughtfully at the test object in the water while Timmins stared just as intently at the pathologist and the two Melfan technicians talked quietly to each other. Suddenly it spoke.
“We need a keel of some kind,” it said in a quiet but excited voice, “but one which will not alter the object’s appearance. The original life-form uses paddles which are translucent and move too quickly to be seen. Why don’t we use an invisible keel?”
Without giving anyone a chance to reply it went on, “We should be able to make it from a shaped and hardened transparent gel possessing the same refractive index as water. It would have to be edible, naturally, and be weak enough structurally not to damage the patient’s teeth or digestive tract. Some of the constituents I have in mind — well, the taste would range from neutral to downright awful, but we can work on that until—”
“You can produce this edible stabilizer?” Gurronsevas broke in, incredulity making him forget good manners. “Your department has done so before?”
“No,” said Murchison. “We have never been asked to do so before. It will be a difficult but not impossible biochemical problem to devise an edible and Chalder-non-toxic material of the required consistency. The shaping of the material into a keel and its attachment to the vehicle will be covered by your food synthesizer programming.”
“Meanwhile,” Timmins joined in, “we can start fitting non-edible and visible keels to the test vehicle to see which size and shape works best. Kledath, Dremon, lift it onto the raft. We’ve got work to do.”
Murchison rolled off the raft so as to give the others more space to work. It lay floating on its back beside Gurronsevas, completely relaxed, with eyes closed and only its face above the surface.
“I think you have solved this problem, Pathologist Murchison,” he said, “and I am most grateful.”
“We aim to please,” the pathologist said. Its mouth opened slightly in a smile and the eyes remained closed. “Have you other problems?”
“Not exactly,” said Gurronsevas. “I have thoughts and questions and ideas, not yet fully formulated, which are likely to develop into problems. Right now my ignorance about some aspects of my future work here is close to total and, well, I would welcome suggestions.”
The pathologist opened one eye briefly to look at him, then said, “Right now I can think of nothing better to do than listen and make suggestions.”
On the raft the three technicians were concentrating all of their attention on the test vehicle, so much so that Timmins had stopped casting sidelong glances at Murchison. They had attached a long, narrow keel and the Lieutenant was suggesting that they add a similar dorsal fin so as to equalize water resistance on the top and undersides. With the expected increase in longitudinal stability, which would reduce the earlier tendency to sideslip and go into a spin every time it changed direction, the lateral thrusters would need to be strengthened so as to sharpen the turning angles.
The conversation could not have been more technical, Gurronsevas thought as he directed all of his eyes towards Murchison, if they had been designing a spaceship.
“Thanks to your suggestion,” he said, “our test object should act as well as look like the food animal it is meant to be. That is important because there is much more to food than its outward appearance. There are also taste, smell, consistency, visual presentation, and contrasting or complementing sauces which, I hope to demonstrate in time, are vital accompaniments to the often bland edible material that the hospital synthesizers provide. In the case of our Chalder we have been able to reproduce the consistency with the hard shell that encloses the soft contents, and the presentation, which is the mobility of a dish that is apparently trying to escape being eaten. But that is all.”
“Go on,” said Murchison, opening both of its eyes.
“In the present instance,” said Gurronsevas, “the difficulty of adding a conventional sauce to a dish that is moving rapidly underwater is well-nigh insurmountable. The thick-shelled, immobile eggs currently being fed to AUGL patients, in spite of the artificial taste additives they contain, are most unappetizing. To an Earth-human like yourself an analogy would be that they taste like cold mashed potato sandwiches …”
“My department was consulted about those artificial taste additives,” Murchison broke in, “to make sure there would be no harmful side-effects. The taste concentration can easily be increased if that is what you want.”
“It isn’t,” said Gurronsevas firmly. “The diner, I mean the patient, is aware of the artificial taste and finds it objectionable. I had it in mind to reduce the taste components in the material rather than increase them, it being more difficult for the sensorium to detect artificially in trace quantities than in heavy concentrations. My plan, or rather my hope, is to mask the diluted artificial taste with a sauce that requires no physical ingredients. Instead I will rely on the best condiment of all, hunger, reinforced by the excitement of the chase and the uncertainty of
