Bollman's 1852 publication was widely disseminated here and abroad and
studied with respectful interest by the engineering profession. Its
drawings of the structure were copied in a number of leading technical
journals in England and Germany. Although there is no record that the
type was ever reproduced in Europe, there can be little doubt that this
successful structural use of iron by the most eminent railroad in the
United States and its endorsement by an engineer of Latrobe's status
gave great impetus to the general adoption of the material. This
influence was certainly equal to that of Stephenson's tubular iron
bridge of 1850 over the Menai Strait, or Roebling's iron-wire suspension
bridge of 1855 over Niagara gorge. The Bollman design had perhaps even
greater influence, as the B. & O. immediately launched the system with
great energy and in great numbers to replace its timber spans; on the
other hand, Roebling's structure was never duplicated in railroad
service, and Stephenson's only once.
[Illustration: Figure 16.--_Left:_ CONJECTURAL SECTION of Bollman's
segmental wrought-iron column, about 1860, and section of the standard
Phoenix column; _right:_ Phoenix column as used in truss-bridge
compression members.]