The Bessemer process of making “mild” steel had for some time been in operation in the Pennsylvania mills, but the output had been limited to steel rails; structural shapes were still rolled out of iron. The Bessemer process itself was revolutionary, and the story of its early trials and tribulations, its ultimate success, form a special chapter in the bible of modern industry.
Now in the process of things we have called a “flow,” and which is frequently spoken of as evolution—a word fast losing its significance—the tall commercial building arose from the pressure of land values, the land values from pressure of population, the pressure of population from external pressure, as has been said. But an office building could not rise above stairway height without a means of vertical transportation. Thus pressure was brought on the brain of the mechanical engineer whose creative imagination and industry brought forth the passenger elevator, which when fairly developed as to safety, speed and control, removed the limit from the number of stories. But it was inherent in the nature of masonry construction, in its turn to fix a new limit of height, as its ever thickening walls ate up ground and floor space of ever increasing value, as the pressure of population rapidly increased.
Meanwhile the use of concrete in heavy construction was spreading, and the application of railroad iron to distribute concentrated loads on the foundations, the character of which became thereby radically changed from pyramids to flat affairs, thus liberating basement space; but this added basement space was of comparatively little value owing to deficiency in headroom due to the shallowness of the street sewers. Then joined in the flow an invention of English origin, an automatic pneumatic ejector, which rendered basement depths independent of sewer levels. But to get full value from this appliance, foundations would have to be carried much deeper, in new buildings. With heavy walls and gravity retaining walls, the operation would be hazardous and of doubtful value. It became evident that the very tall masonry office building was in its nature economically unfit as ground values steadily rose. Not only did its thick walls entail loss of space and therefore revenue, but its unavoidably small window openings could not furnish the proper and desirable ratio of glass area to rentable floor area.
Thus arose a crisis, a seeming impasse. What was to do? Architects made attempts at solutions by carrying the outer spans of floor loads on cast columns next to the masonry piers, but this method was of small avail, and of limited application as to height. The attempts, moreover, did not rest on any basic principle, therefore the squabblings as to priority are so much piffle. The problem of the tall office building had not been solved, because the solution had not been sought within the problem itself—within its inherent nature. And it may here be remarked after years of observation, that the truth most difficult to grasp, especially by the intellectuals, is this truth: That every problem of whatsoever name or nature, contains and suggests its own solution; and, the solution reached, it is invariably found to be simple in nature, basic, and clearly allied to common sense. This is what Monsieur Clopet really meant when he said to Louis in his Paris student days: “Our demonstrations will be such as to admit of no exception.” Monsieur Clopet carried the principle no further than his mathematics, but Louis saw in a flash the immensity and minuteness of its application, and what a world of research lay before him; for with the passing of the flash he saw dimly as through a veil, and it needed long years for the vision to reclarify and find its formula.
As a rule, inventions—which are truly solutions—are not arrived at quickly. They may seem to appear suddenly, but the groundwork has usually been long in preparing. It is of the essence of this philosophy that man’s needs are balanced by his powers. That as the needs increase the powers increase—that is one reason why they are herein called powers.
So in this instance, the Chicago activity in erecting high buildings finally attracted the attention of the local sales managers of Eastern rolling mills; and their engineers were set at work. The mills for some time past had been rolling those structural shapes that had long been in use in bridge work. Their own ground work thus was prepared. It was a matter of vision in salesmanship based upon engineering imagination and technique. Thus the idea of a steel frame which should carry all the load was tentatively presented to Chicago architects.
The passion to sell is the impelling power in American life. Manufacturing is subsidiary and adventitious. But selling must be based on a semblance of service—the satisfaction of a need. The need was there, the capacity to satisfy was there, but contact was not there. Then came the flash of imagination which saw the single thing. The trick was turned; and there swiftly came into being something new under the sun. For the true steel-frame structure
