It is the ideal land for tuberculosis, though all invalids should be examined as to heart action before attempting any altitude over 4,000 feet. And the Southwest has worked out an ideal system of treatment for tuberculosis patients. They are no longer housed in stuffy hotels and air tight, super-heated sanitariums. Each sanitarium is now a tent city--portable houses or tents floored and boarded halfway up, with the upper half of the wall a curtain window, and a little stove in each tent. Each patient has, if he wants it, a little hospital all to himself. There is a central dining-room. There is also a dispensary. In some cases, there are church and amusement hall. Where means permit it, a family may have a little tent city all to itself; and they don't call the tent city a sanitarium. They call it "Sun Mount," or "Happy Canyon," or some other such name. The percentage of recoveries is wonderful; but the point is, the invalids must come in time. Wherever you go along the borders of Old and New Mexico searching for prehistoric ruins, you come on these tent cities. [Illustration: The Enchanted Mesa of Acoma, as high as three Niagaras, and its top as flat as a billiard table] Where can one see these cliff and cave dwellings of a prehistoric dwarf? Please note the points. Cliff and cave dwellings are not the same. Cliff dwellings are houses made by building up the front of a natural arch. This front wall was either in stone or sun-baked adobe. Cave dwellings are houses hollowed out of the solid rock, a feat not so difficult as it sounds when you consider the rock is only soft pumice or tufa, that yields to scraping more readily than bath brick or soft lime. The cliff dwellings are usually only one story. The cave dwellings may run five stories up inside the rock, natural stone steps leading from tier to tier of the rooms, and tiny porthole windows looking down precipices 500 to 1,000 feet. The cliff dwellings are mostly entered by narrow trails leading along the ledge of a precipice sheer as a wall. The first story of the cave dwellings was entered by a light ladder, which the owner could draw up after him. Remember it was the Stone Age: no metals, no firearms, no battering rams, nor devices for throwing projectiles. A man with a rock in his hand in the doorway of either type of dwelling could swiftly and deftly and politely speed the parting guest with a brickbat on his head. Similar types of pottery and shell ornament are found in both sorts of dwellings; but I have never seen any cliff dwellings with evidences of such religious ceremony as in the cave houses. Perhaps the difference between cliff folk and cave folk would be best expressed by saying that the cliff people were to ancient life what the East Side is to us: the cave people what upper Fifth Avenue represents. One the riff-raff, the weak, the poor, driven to the wall; the other, the strong, the secure and defended.