So far we have been considering largely features either of equipment or train control. Perhaps more important than these is the permanent way. Compared with engines, cars, signals and dispatching, the variety of problems presented in the construction and maintenance are many. We perhaps owe to the ancient beginnings and highly scientific development of the profession of civil engineering and its branches the fact that these problems of construction and maintenance are so well met and the source of so little anxiety in connection with railroad transportation at the present time. American engineering ingenuity and courage have devised structures to meet every requirement of railroad development. In bridge construction for centuries the simple beam or the arch were the only spans employed. The natural barriers to construction of railroads required something more than either. Between 1830 and 1850 many wooden trusses were built in the Eastern and Middle States after the design of Burr and Palmer. S. H. Long's introduction of counter-braces in truss construction in 1830 was a long step in advance, and after ten years the celebrated Howe truss was brought out by the inventor. Four years later came the Pratt truss. In 1859 several riveted lattice trusses were built for the New York Central, varying from 40 to 90 feet in length, by Howard Carroll. The Lehigh Valley built a Whipple-Murphy pin-connected bridge of 165-foot span. This progress in truss construction enabled the railroads to bridge streams and secure continuous roadway. As an interesting historical note in connection with railroad bridges, we find that the first railroad bridge was built across the Mississippi River at Rock Island in 1856. It had hardly been completed, at great expense, before St. Louis steamboat interests demanded its removal as a nuisance and an obstruction to navigation. The United States District Court so adjudged it, and ordered its removal within six months. The presiding judge in his opinion stated that "if one railroad is able to transfer freight and passengers without delay and expense of changing at the river, financial necessity will compel competing roads to provide themselves with the same facilities," which led him to foresee great interference to river traffic and great mischief in the establishment of such a precedent. The case was appealed, and Abraham Lincoln was the counsel for the bridge company before the United States Supreme Court. He argued that both the river and the railroad were great highways for the people, and while at the immediate time the water traffic was possibly greater, he predicted that the time might come when the railroads might equal or exceed the traffic on the river, and he consequently felt that each interest was entitled to equal consideration. His broad grasp of the subject secured for his company a reversal of the decision of the lower court, and the bridge remained.