'What is this?' I asked. 'It is the axle of one of Weston's great wheels,' answered Grayson. 'It has never ceased to revolve for two hundred years.'
'Strange that it has not worn out in that time.'
'Had these been common steel and common bronze they would have been, but these metals are so tempered that a diamond will not cut them. There are three of these wheels here, and several more at low places on the plain. They are each one hundred feet in diameter and twelve feet wide. They scoop up the water and pour it into the aqueduct.'
We went through another door into a larger room that contained a model of the three wheels. It was set in motion, by a small electric motor, a reduced model of the one that drives the wheels. The one needs but a thread to drive it; the great one has its power carried by a thick cable. From one end of the model room we can look down into the cistern that catches the water from a score of great drains, and we can see the ascending buckets so slung that the movement of the great wheel does not spill the water back again until the proper place for tilting is reached. Were it not for these wheels much of the great plain would again become swampy. The water thrown up by these wheels is sufficient to make a respectable river to begin with. About a mile down stream the water flows very slowly, and the river is deep and clear. From this point it is used as a waterway for the carriage of produce, manures, etc. Railway lines run under the rivers at many points. 'This great work is one that no syndicate or company could have undertaken. It is one that would heavily tax the resources of a great nation. Such works are only possible to a peaceful federation of nations,' says Grayson, as we came away, 'and on your planet there are several such works waiting for the time when international action is possible. For instance, which nation will attempt to make Sahara into a sea, while its possession might have to be fought for by several European powers?'
Two hours later we were dining at Port Howard, and in another hour our great boat, with some two thousand passengers on board, was swiftly moving across the central ocean.
CHAPTER XII.
More Wonders.
WE who dwell in Mars, a planet that has lost its water surfaces to some extent and increased its land in like proportion, do not travel much by sea. Millions never see the oceans, even though they travel at times a good deal. Still, in so vast a population of happy and healthful people living under a benign and well nigh perfect legislation, there are many who travel for information and pleasure, and many whose occupation necessitates constant movement. Some spend the greater part of their forty-nine days
