what they expect to. It will be as if their metre, already shortened one half, were reduced another half. Hence the acre they may devote to the cultivation of flax or hemp or cotton will fall far short of furnishing them as many shirts.
With respect to measures of capacity and weight: On the earth Megamicros quenched his thirst with two litres of wine. These two litres restored to him the quantity of liquid which he lost by transpiration and excretion. Without speaking of excretions, the Martian man will lose perceptibly more by evaporation alone than he did on the earth; for while his mass is reduced to one eighth, his surface is only reduced to one fourth. He will, therefore, lose twice as much by transpiration as he did before, and a litre of wine will not seem to contain more than half the same sum of satisfaction. For a like reason, a kilogramme of bread will not appease hunger in the same measure as on the earth. For food, besides furnishing energy to the muscles, serves, by repairing the loss of caloric, to maintain the animal heat. The cooling surface of the body is twice as great in proportion to the mass; the kilogramme of bread will, therefore, not procure the same sum of muscular energy. We know, as a fact, that small animals have to eat and drink relatively more than large animals.
Megamicros will feel a change of temperature on Mars more than when he was on the earth. He gets cool and is warmed again in less time, when all other things are equal. If a cloud passes over the sun, he will immediately feel a depression of the temperature of his skin. It is a very sensitive thermometer. Two thermometers, geometrically alike, do not act in the same manner. There is no synchronism in their movements. All such disagreements arise from the fact that surfaces do not diminish in the same proportion as volumes.
The problem becomes more and more complicated as we address ourselves to more delicate phenomena. Muscular energy is due to the burning by oxygen of the carbon contained in the blood. This combustion is effected on the surface of the lungs. The quantity of blood of a Martian is eight times less than that of a being of the earth. But while the thoracic cage is diminished in the proportion of eight to one, the pulmonary surface is so only in the proportion of four to one. The combustion is therefore more complete with the Martian than with the man of the earth. Consequently his muscular energy, the effects of which were already so striking in consequence of the reduction of weight, will be still more marked by virtue of this circumstance. On the other hand, combustion being more active, the kilogramme of bread, which we have already found not enough, becomes still more insufficient—a new pertur-
