Engineering Wonders of the World
Volume I

4 ENGINEERING WONDERS OF THE WORLD. architects and engineers should have made no attempt to apply the system to building con- struction until it had been imported as a ’cute American notion. The first form of metal-frame build- ing in the United States is said to have originated in California about 1867, when iron frames were con- structed within the walls of buildings for the purpose of preventing rupture by earthquake. In 1882 Mr. W. L. B. Jenny was commis- sioned to design a ten-story building in Chicago. It had to give accommo- dation below for two banks, and above for small, well-lighted offices. Fig. 8.—POSING FOR PHO- TOGRAPH ON THE HIGH- EST POINT OF A FORTY- STORY BUILDING. {Photo, Illustrations Bureau.)- These requirements, coupled with the condition of a very com- Development. pressible soil, necessitated a novel method of construction, including narrow piers to give proper window space and thin walls to allow sufficient room for the foundations. To thicken the piers into the building would have been objectionable, and the natural solu- tion was to build an iron column in each pier to carry the floor loads. This entailed a diffi- culty arising from the fact that the iron and brickwork had different factors of expansion. So Mr. Jenny went a step further, and de- signed columns to bear the walls as well as the floors. Thus the final design comprised a complete cage, consisting of columns and girders, the outer walls being split up into separate panels, each carried by a wall girder, or lintel ; and Mr. Jenny may therefore be regarded as the originator of the cage system used in modern building construction. The Drexel Building, Philadelphia, designed in 1887 by Mr. Joseph M. Wilson, is a good instance of steel skeleton construction, having columns in the outer walls connected with and sustaining the floor girders. By designing the frame to carry the floors and partition walls independently in each story, it became pos- sible to adopt any desired arrangement of the rooms without reference to the disposition of those on other stories. The first example of the cage in New York was the Tower Building of eleven stories de- signed by Mr. B. L. Gilbert in 1888. A very im- portant feature of steel-frame construction is that of speed. Speed in Construction. To those familiar with British methods only, the completion of the roof be- fore the walls are finished would appear an Fig. 9.—FIXING A DERRICK FORTY STORIES ABOVE BROADWAY. [Photo, Illustrations Bureau.) absurdity. But in practice it is possible and usual to work on this apparently cart-before- the - horse plan in the erection of a sky-