PLACEHOLDER Railroad Air Brake and Signal Chart. Material: paper. Size: 12" W. x 18 11/16" L. Description: purple cover with white print title information: Westinghouse Diagramatic and Sectional Views of Air-Brake and Air Signal Instructional Charts, prepared and published by Fred McArdle and Henry Helmholtz, copyrighted 1909 for air brake and air signals of railroad steam engines. 33 pages.
