_Primitive Shelters and Houses_.--The shelters of primitive man were more or less temporary, for wherever he happened to be in his migrations he sought shelter from storm or cold in the way most adaptable to his circumstances. There was in this connection, also, the precaution taken to protect against predatory animals and wild men. As his stay in a given territory became more permanent, the home or shelter gradually grew more permanent. So far as we can ascertain, man has always been known to build some sort of shelter. As apes build their shelters in trees, birds build their nests, and beavers dam water to make their homes, it is impossible to suppose that man, with superior intelligence, was ever simple enough to continue long without some sort of shelter constructed with his own hands. At first the shelter of trees, rocks, and caves served his purpose wherever available. Subsequently, when he had learned to build houses, their structure was usually dependent more upon environment than upon his inventive genius. Whether he built a platform house or nest in a tree, or provided a temporary brush shelter, or bark hut, or stone or adobe building, depended a good deal upon the material at hand and the necessity of protection. The main thing was to protect against cold or storm, wild animals, and, eventually, wild men. The progress in architecture among the nations of ancient civilization was quite rapid. Massive structures were built for capacity and strength, which the natives soon learned to {100} decorate within and without. The buildings were made of large blocks of hewn stone, fitted together mechanically by the means of cement, which made secure foundations for ages. When in the course of time the arch was discovered, it alone became a power to advance the progress of architecture. We have seen pass before our eyes a sudden transition in dwelling houses. The first inhabitants of some parts of the Western prairies dwelt in tents. These were next exchanged for the "dugout," and this for a rude hut. Subsequently the rude hut was made into a barn or pig-pen, and a respectable farmhouse was built; and finally this, too, has been replaced by a house of modern style and conveniences. If we could consider this change to have extended over thousands of years, from the first shelter of man to the finished modern building, it would be a picture of the progress of man in the art of building. In this slow process man struggled without means and with crude notions of life in every form. The aim, first, was for protection, then comfort and durability, and finally for beauty. The artistic in building has kept pace with other forms of civilization evinced in other ways.