The early English houses were built of heavy oak-trees. Later half-timber houses used smaller structural members and more standard sizes. These traditions were brought to this country, but it was soon found that heavy oak was not necessary for their stability, but that some of the native soft woods would answer the purpose. The thinning-down process continued, until we developed the frame dwelling of balloon construction which is practically built of 2 by 4 pieces throughout. We are now having a building code formulated by the United States Department of Commerce, which is intended to establish the minimum requirements for small-house construction, so that greatest economy of material can be secured, but also a precedent set for the minimum cutting down of material in building. In the compilation of this code this tendency to reduce the quantity of material used was very evident in the discussions which centred around the problem of whether the brick walls for small houses should be 12 or 8 inches thick. In Colonial days they thought nothing of building them 2 feet thick. To-day we hesitate at building them as thick as 12 inches. In fact, our building codes show no uniformity of opinion on the matter, and our experts disagree. The preliminary form of the above-mentioned code has settled upon an 8-inch thickness for walls not exceeding 30 feet, and made additional allowance for an extra 5 feet in height on the gable end of the building. The process of thinning down is still going on, as this indicates. The illustrations representing briefly the historical progress of styles in domestic architecture in the United States are given to show how these styles have varied, and impress the reader with the rather constant undercurrent of construction methods throughout these changes. In the early Colonial houses the wooden frames were built of heavy oak timbers which were hewn into shape and dressed down with the adze. Sometimes rafters and joists were sawn, and the further along we progress in time the more we find the saw being used. [Illustration: AMERICAN DOMESTIC] [Illustration: AMERICAN DOMESTIC] [Illustration: AMERICAN DOMESTIC]