Our story takes us back many thousands of years to Egypt, the cradle of civilization. From Egypt it will take us to Greece, thence to Rome, thence to the countries of Northern Europe, thence to America. What kind of houses did the Egyptians first build? They built as simple a structure as can be imagined; they erected four walls and over these they placed a flat roof (Fig. 5). The roof was made flat because in Egypt there is scarcely any rain and there was no need for a roof with a slant. In all those countries where rain seldom falls, or never falls, the flat roof is the natural roof (Fig. 6). Although their buildings were simple in construction the Egyptians left behind them most remarkable specimens of the builder's art. Their pyramids and monuments and sphinxes and palaces have always been foremost among the great wonders of the world. Figure 7 shows the interior of an ancient Egyptian palace. This palace had only an awning for a roof. That was all that was necessary to keep out the rays of the sun. Notice the lofty pillars or columns of this building. You see they are adorned above or below with the figure of the lotus, the national flower of the Egyptians. The column, as we shall see, plays an important part in the history of the house and it was ancient Egypt that gave the world its first lessons in the art of making columns. From Egypt we pass over "the sea" to Greece. The Greeks borrowed ideas wherever they could and in the matter of architecture they borrowed heavily from Egypt. But they did not borrow the flat roof of the Egyptians. In Greece there was some rainfall and this fact had to be taken into account when building a house; the roof had to slant so that the rain could run off. Now the Greeks taught the world the best way to make a slanting roof. They made the roof to slant in two directions from a central ridge (Fig. 8) instead of having the entire roof to slant in one direction like an ugly shed. The slant was gentle because there was no snow to be carried off. The roof of two slants formed a gable. The Greeks, then, were the inventors of the _gable_. The column they borrowed from Egypt. But whenever the Greeks borrowed an invention or an idea they nearly always improved upon it. Instead of slavishly imitating the Egyptian columns they tried to make better ones and they were so successful that they soon became the teachers of the world in column making. [Illustration: FIG. 8.--A GREEK DWELLING.] [Illustration: FIG. 9.--THE THREE ORDERS OF COLUMNS.]