John Dolittle, as usual, went after that problem too with much energy. He was a very excellent mathematician, was the Doctor. And one afternoon he sat down with a note book and the Nautical Almanac and worked out tables which should tell him from the stars where he was and in what direction he was going. It was curious, that strange sense of comfort we drew from the stars. They, the heavenly bodies which from the Earth seemed the remotest, most distant, unattainable and strangest of objects, here suddenly became friendly; because, I suppose, they were the only things that really stayed the same. The stars, as we saw them from the Moon, were precisely as the stars we had seen from the Earth. The fact that they were nearly all countless billions of miles away made no difference. For us they were something that we had seen before and knew. [Illustration: “_We rigged up weather-vanes_”] It was while we were at work on devising some contrivance to take the place of the compass that we made the discovery of the explosive wood. The Doctor after trying many things by which he hoped to keep a definite direction had suddenly said one day: “Why, Stubbins, I have it.—The wind! It always blows steady—and probably from precisely the same quarter—or at all events with a regular calculable change most likely. Let us test it and see.” So right away we set to work to make various wind-testing devices. We rigged up weather-vanes from long streamers of light bark. And then John Dolittle hit upon the idea of smoke. “That is something,” said he, “if we only place it properly, which will warn us by smell if the wind changes. And in the meantime we can carry on our studies of the Animal Kingdom and its languages.” So without further ado we set to work to build fires—or rather large smoke smudges—which should tell us how reliable our wind would be if depended on for a source of direction. THE ELEVENTH CHAPTER We Prepare to Circle the Moon We went to a lot of trouble working out how we could best place these fires so that they should give us the most satisfactory results. First of all we decided with much care on the exact position where we would build them. Mostly they were on bare knolls or shoulders, where they couldn’t spread to the underbrush and start a bush-fire. Then came the question of fuel:—What would be the best wood to build them of? There were practically no dead trees, as I have said. The only thing to do then was to cut some timber down and let it dry.