The following day was set aside for a visit to the Accelerated Plant Growing Farms. It had been known for hundreds of years that certain plants, such as mushrooms, could be fully developed in a few days. Plant or vegetables grown under glass and the temperature within kept at a high point, would grow at great speed and be ready for the market long before those grown in the open. But only recently, as Ralph explained to Alice, had it been possible to do this on a large scale. To be sure, certain vegetables, like asparagus, lettuce, peas, etc., had been produced in hothouses for hundreds of years, but these, after all, were rather luxuries, and could not be classed as essentials.
When, about the year 2600, the population of the planet had increased tremendously and famines due to lack of such essentials as bread and potatoes had broken out in many parts of the world, it was found vitally necessary to produce such necessities on a larger scale and with unfailing regularity. These farms became known under the term of Accelerated Plant Growing Farms and were located in every part of the world. The first (and now obsolete) European and African farms were built along the lines of the old-fashioned hothouses. The European farms were simply horizontal steel-latticed roofs, with ordinary[Pg 98] glass panes, permitting the sunlight to penetrate to the soil beneath. While covering huge acreages, they were not heated artificially, using only the sun's rays to accelerate plant growth. As compared with Nature's single crop of wheat or corn, two could be made to grow in the same season by means of these super hothouses.
Similar farms were used in America until Ralph undertook their study and approached the subject from a scientific angle. One of his first efforts was to obtain greater heat for these huge hothouses. One of these hothouses is about three miles long and the same width. Ralph took the existing hothouses, which were simply oblong steel and glass boxes, and built a second hothouse box covering each of them, thus creating a double-walled, air-locked hothouse. The second glass-paneled wall was about two feet inside the outer one. This left dead air locked between the walls, and as air is a poor heat conductor, the heat in the hothouse was retained longer, particularly during a cold night.
Ralph and Alice left early in the morning, winging their way in an aeroflyer toward northern New York, where there were many Accelerated Plant Growing Farms. When the farms came into view, the entire country below, so far as the eye could see, appeared to be dotted with the glass-covered roofs of the plants, reflecting the sunlight and affording an unusual sight. Alice marveled at their number, for while she had seen some of these farms in Europe, she had never seen so many grouped together of such immensity.
Within a few minutes, they landed near one of the giant hothouses. The manager led them inside of the farm labeled No. D1569.
[Pg 99]
D1569 was exclusively a wheat growing farm. Where Mother Nature used to grow one crop of wheat a year, Ralph's latest Accelerator made it possible to grow four, and sometimes five crops a year. In the old-fashioned European farms such as Alice knew, only two crops could be grown.
"How is it possible," she asked, "that you can obtain three more crops a year than we do in Europe?"
"In the first place," said Ralph, "it may be taken as an axiom that the more heat you supply to plant growth, the quicker it will grow. Cold and chilly winds retard plant growth. Electricity and certain chemicals increase the ratio of growth, a fact that has been known for many centuries. It is, however, the scientific application of this knowledge that makes it possible to raise five crops a year. The European farms use only the heat of the sun to stimulate plant growth, but during the night, when the temperature drops, growth is practically nil.
"Notice that the top and sides of our hothouses have two walls. In other words, one hothouse is built within another. The air locked between the two hothouses is an excellent heat insulator and even though the sun is low at 4 o'clock, the temperature is practically unchanged in the hothouse, at 8 or 9 o'clock in the evening. Even in the winter, when the sun sets about 4 o'clock and it is cold, we are able to store up enough heat during the day to keep a high temperature as late as 7 and 8 o'clock. If we did nothing between the hours of 8 in the evening and 8 in the morning, the temperature would continue to fall to a point where no plant growth would be possible.
"Here in America we had to have a greater production to supply our huge population. It was a pure case of ne[Pg 100]cessity. So we had to employ artificial heating during the night.
"If we start sinking a shaft into the earth, the heat increases rapidly as we go down—more quickly in some parts of the world than others. On an average, the temperature rises about one degree Fahrenheit each 100 feet of depth. We found it economic, therefore, to use the earth's own heat to heat our farms.
"By means of high speed drills, we can cut a three-foot shaft 3,000 feet deep in the earth in less than a month. We go down until we strike a temperature around 100 to 120 degrees Fahrenheit. Then we lower steel tanks into the cavity and run pipes up to the surface. The tanks are filled with water and two larger pipes run from each tank into the circulating system of pipes, around the lower walls throughout the length and breadth of the farms. The shafts are then closed at the top and we have a circulating system that is both cheap and efficient. The hot water continually rises into the pipes and circulates. As it cools, it flows down again into the tanks, where it is reheated and rises again. Thus the temperature of our farms is uniform all the year around and plant growth is as rapid during the night as during the day.
"Heat alone, however, is not sufficient. We should still get only a normal growth. We wanted five crops a year. I put my research forces to work studying fertilizers. While the old nitrogen fertilizers were excellent, they were not suitable for high pressure, high speed growing methods. We evolved chemicals which were both cheap and easy to apply. We found that small quantities of Termidon, when mixed with water and sprayed over the field by overhead sprayers, which you will see running along[Pg 101] the ceiling, would accelerate the growth of the crops enormously.
"This liquid Termidon is sprayed over the entire length and breadth of the field before planting time, so that the soil becomes well soaked. The Termidon immediately turns the soil into a rich, dark strata, the best soil for potatoes, wheat, or corn. No other fertilizer need be used, the Termidon, applied after every growth, giving the soil all the vitality necessary."
They were now in the field, when suddenly Alice asked:
"What is the peculiar tingling in the soles of my feet, I feel as we walk along? You are using some electrical vibrations, I suppose."
"You guessed correctly," Ralph replied. "With all our artifice the speed of the plant growth had not been accelerated sufficiently. I therefore insulated the inside hothouse from the ground. The inside hothouse rests upon glass blocks, and is electrified by high frequency currents. The entire area is sprayed day and night with a high frequency current, in the use of which we found was the real secret of driving plant growth ahead at enormous speed. The theory of course is nothing new, having been known for centuries. What is new, however, is the way it is done. It makes all the difference in the world if the current density is too high or too low, if it is direct or alternating current, and many other details. I found that the quickest way to accelerate plant growth by electricity was to send the current from the growing plant toward the ceiling, and the current must be direct, pulsating, but not alternating."
Ralph asked for a discharge pole from one of the at[Pg 102]tendants. It was a metal pole about seven and a half feet high. In the middle it had a long glass handle which Ralph grasped. He then set the pole vertically so that its top was about six inches from the glass ceiling. A roar of fine sparks leaped from the steel frame of the ceiling to the top of the pole.
"See," said Ralph, "there is the current we use in accelerating the growth of our plants."
Removing the pole, Ralph continued: "The electrical current density per square foot is not very high and the wheat does not get a very great amount of electricity during the twenty-four hours. The continuance of the force applied is what counts."
After luncheon, during which they ate some of the bread made from wheat grown on the premises, they went to an adjoining farm, also a wheat farm, where harvesting was in full progress. Machinery, suspended from overhead tracks, cut the wheat rapidly with circular scythes. All the wheat being of the same height, the machine cut the wheat almost directly below the heads, dropped them on a conveyor, which carried the real harvest to a central distribution point. Another machine immediately followed the cutter, grasping the stalks that were still standing, unerringly pulled out the straw hulks, roots and all. Thus the roots were entirely removed and the soil loosened, obviating plowing. Within a few hours following cutting, the last stem was out. The field was then sprayed with the liquid Termidon from overhead. Within another three hours, sowing began, also from overhead pipes.
Going to an adjoining plant, they saw a bare field with almost black soil, ready to be sowed. An attendant, at Ralph's request, pulled a switch and immediately Alice[Pg 103] witnessed a seed rain from the overhead pipes.
"The seed," Ralph explained, "is supplied to these tubes by means of compressed air. The tubes are perforated, and when air pressure is applied, the seed, flowing through the tubes is ejected evenly—just so many seeds to a given area. Closing the openings of the pipes automatically as the seeding proceeds, means only a given quantity of seed will fall upon any given square foot of soil. This makes for scientific planting, and we raise just the exact quantity of wheat we want."
Alice watched the seed ra............