684 POPULAR SCIENCE MONTHLY. 



what they expect to. It will be as if their metre, already shortened 

 one half, were reduced another half. Hence the acre they may de- 

 vote 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- 



