Railroad viaducts and trestles Railroads, the transportation mode that revolutionized the 19th century, generated a bridge type that merits special attention. The limited traction of locomotives forced the railroad engineer to design the line with easy gradients. Viaducts and trestles were the engineering solution for maintaining a nearly straight and horizontal line where the depth and width of the valley or gorge rendered embankments impracticable. These massive, elevated structures were first built in Roman style of multiple-stone arches and piers. Later, when wrought iron and steel became available, engineers built viaducts and trestles of great length and height on a series of truss spans or girders borne by individual framed towers composed of two or more bents braced together. Figure 13 Thomas Viaduct (1835), Relay, Maryland (USA). This illustration from The United States
clearest test of this possibility would come from the records of automobile crashes involving a single car and a lone driver, Phillips compared the age of the suicide- story victim with the ages of the lone drivers killed in single-car crashes immedi- ately after the story appeared in print. Once again the predictions were strikingly accurate: When the newspaper detailed the suicide of a young person, it was young drivers who then piled their cars into trees, poles, and embankments with fatal re- sults; but when the news story concerned an older person's suicide, older drivers died in such crashes (Phillips, 1980). This last statistic is the clincher for me. I am left wholly convinced and, simul- taneously, wholly amazed by it. Evidently, the principle of social proof is so wide- ranging and powerful that its domain extends to the fundamental decision for life or death. Phillips' findings illustrate a distressing tendency for suicide publicity to
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