Edgar Rice Burroughs: A Princess of Mars

20. CHAPTER XX: IN THE ATMOSPHERE FACTORY (continued)

He led me to an inner chamber where I beheld a battery of twenty radium pumps any one of which was equal to the task of furnishing all Mars with the atmosphere compound. For eight hundred years, he told me, he had watched these pumps which are used alternately a day each at a stretch, or a little over twenty-four and one-half Earth hours. He has one assistant who divides the watch with him. Half a Martian year, about three hundred and forty-four of our days, each of these men spend alone in this huge, isolated plant.

Every red Martian is taught during earliest childhood the principles of the manufacture of atmosphere, but only two at one time ever hold the secret of ingress to the great building, which, built as it is with walls a hundred and fifty feet thick, is absolutely unassailable, even the roof being guarded from assault by air craft by a glass covering five feet thick.

The only fear they entertain of attack is from the green Martians or some demented red man, as all Barsoomians realize that the very existence of every form of life of Mars is dependent upon the uninterrupted working of this plant.

One curious fact I discovered as I watched his thoughts was that the outer doors are manipulated by telepathic means. The locks are so finely adjusted that the doors are released by the action of a certain combination of thought waves. To experiment with my new-found toy I thought to surprise him into revealing this combination and so I asked him in a casual manner how he had managed to unlock the massive doors for me from the inner chambers of the building. As quick as a flash there leaped to his mind nine Martian sounds, but as quickly faded as he answered that this was a secret he must not divulge.

>From then on his manner toward me changed as though he feared that he had been surprised into divulging his great secret, and I read suspicion and fear in his looks and thoughts, though his words were still fair.

Before I retired for the night he promised to give me a letter to a nearby agricultural officer who would help me on my way to Zodanga, which he said, was the nearest Martian city.