A Great Building.
Mr. J. L. Smithmeyer, architect of the Congressional Library building, states in his first annual report that the Congressional Library building when completed will be the largest structure in Washington, with the exception of the Capitol. It will cover 111,000 square feet of space.
In a building of such magnitude and importance, every step in the progress of the work must be carefully considered, lest fatal mistakes, due to hasty construction, should occur. It was deemed of the utmost importance to test every foot of ground supporting the foundation walls. For this purpose a traveling testing machine was constructed, which will give an accurate test of the entire soil. The tests thus far made have been most satisfactory, the soil standing a maximum pressure of 13·5 tons to the square foot, only 2·5 tons being required. These tests will be continued until the foundations are laid.
The method of testing the soil and putting in the concrete foundations may be briefly described as follows: First, the trench excavations are made by the contractor to the width and depth required by the plans, the bottom of the trenches being made perfectly level. Then the testing machine, consisting of a car bearing the required amount of weight in pig lead for making the tests, is placed in the trenches upon iron rails, which rest upon four cast iron pedestals, the latter being set four feet apart each way, each pedestal covering one foot of ground. Thus, one‐fourth of the entire weight borne by the car rests upon each one of the pedestals, and the precise weight sustained by each square foot of ground is exactly determined. The soil being thus tested as to its resisting strength, is then ready to receive the concrete foundations.