“Your astronomers do not consider that animal life and activity depend, not on the amount of air the animal is surrounded by, but by the amount of it he can use. The fishes in your waters have less air to the cubic foot of space than we have, yet are active, but if you take them out of the water and surround them with ten times as much air as they had, they nevertheless die, because they have not lungs suitable for breathing it. But furthermore it is not the amount of air that is of such consequence to animal life, but the amount of oxygen. Your air consists of about 21 parts of oxygen to 79 of nitrogen, and mixed with it is a considerable amount of carbonic acid and other impurities. In our air the proportions of nitrogen and oxygen are about reversed, and there is a far less amount of carbonic acid gas. There is also a much greater quantity of ozone, which as you know, is a concentrated and more active form of oxygen. And so on the whole, when I take a breath of air here on your earth, I get but a slightly greater quantity of oxygen than at home.”
“Then you are not greatly inconvenienced in being transferred from lunar conditions to those of earth?”
“Well, not with respect to breathing, but when we are at the surface of the earth we are greatly oppressed by the weight of your atmosphere and by our own increased weight as well. Ten or fifteen minutes is as long as we can stand it at one time. But we can get speedy relief by ascending ten thousand miles or so, and when we have come to earth to make extended studies of things here, we are compelled to interrupt them by frequently going up and remaining awhile.”
I had become not only intensely interested in the extraordinary information communicated by my visitor, but greatly fascinated by his person and presence; and his last speech made me painfully apprehensive that I was about to lose his company, and so I expressed the wish that if he felt obliged to go up stairs to recover himself, he would return and continue the interview as soon as possible. He replied that he would be compelled to return home as soon as he left me, but added that he would remain with me for a considerable time longer, observing that he felt exceedingly glad to impart information to so willing a listener. I could not at the time reconcile his intention of remaining a considerable time longer with what he said about not being able to remain at the earth’s surface more than ten or fifteen minutes at a time, as I thought he had already considerably exceeded that. But not wishing to lose time by having him reconcile his observations, I hastened to get back to the thread of his discourse, by asking what sort of food the Lunarians live on.
“The Lunarians are exclusively vegetarians and live chiefly on grains and grasses and leguminous plants in some degree resembling those on earth, but of an entirely different habit, for they all or nearly all, mature in the period of one-half of a lunar month or about fourteen of your days. But this will not seem so surprising, when you reflect that we have continuous sunshine without night during the whole time. Of course this observation applies only to the exterior continent on the further half of the moon. Our plants were all developed on that side and became adapted to the seasons there, and they generally retain their habits of growth since their introduction to the interior continent, or Pocket. But in many cases, by changing the conditions of nourishment, new varieties have been developed, having a longer or shorter period of growth. Much more than half of our food products are produced under extremely artificial conditions. The artificial heat we require for cooking, for warmth etc., is produced by means of electricity and so is our artificial light; moreover, we do not allow any organic matter, such as dead bodies, dead trees or vegetables or any sort of refuse or excrete matters, to rot either in the open air or in the ground, and the manuring of the soil is strictly forbidden. Our air therefore is very poor in carbonic acid gas, (or carbonic dioxide), which constitutes almost the sole food required for the growth of plants. In fact about all that the air gets of this gas is that thrown off from our lungs in breathing. To use this up, we cultivate various air plants that grow with little or no roots and yet cover the ground with an agreeable carpet. Some of these are eatable. All organic matters, when they become refuse, are carefully collected in great air tight and powerful tanks, in which they are heated under an enormous pressure until their original organization entirely disappears. The dimensions of the tanks are reduced during this process by the gradual forcing in of the walls, which are made movable for that purpose, and when the contained material has become reduced to about the consistency and constitution of your ordinary lignite or soft coal, it is forced through a number of cylindrical holes on one side of the tank, by which it is moulded into round sticks of coal, and is then ready to be used over again. The whole process is an imitation of that by which mineral coal is produced in nature, both on the earth and the moon, except that it is accomplished artificially with us in about 50 hours, while nature takes thousands of years for it. The fluids and nitrogenous and other volatile substances pressed out, are secured and saved by proper absorbents. These together with the coal are used by our food growers in producing their plants.
“The planting is all done in vats or chambers with air tight roofs. The bottom of a vat is covered with a few inches of soil specially prepared and appropriate for the plant intended to be sown. After the seeds germinate the vat is covered and the inside is brightly illuminated with electricity and filled with carbonic dioxide, obtained by burning a proper quantity of coal in a retort, which is also accomplished by electricity. All the conditions necessary for rapid growth are supplied to the plants and they are forced forward to maturity without any pause or delay, such as takes place in the growth of plants on earth, through the intervention of cloudy or stormy weather, too much or too little moisture, too much or too little heat, the darkness of night etc.
“The same method of cultivation prevails to a great extent on the exterior continent, although as the sun shines on that continent about 350 hours at a time, which constitutes the length of the day there, the vats are often merely covered by air tight glass roofs and the sun is the growing power instead of electricity.”
“I understand now,” said I, “what you meant by saying you reserved your mineral coal for food purposes. You draw on it only when the steady supply of artificial coal fails?”
“That is correct.”
“But if you rigorously save every particle of your organic matters to be reconverted into food, I don’t see why it should ever fail unless your population increases. But you have not informed me on that subject.”