A monumental discovery, air brakes were a turning point in history by drastically changing the world's safety standards through one invention and contributing to the growth of the United States.
This is a drawing of an air brake applicator. When the operator applies the brakes, he or she is actually decreasing air pressure. Click for larger image. Wikipedia.
This is a typical 1860's to 1880's passenger train. This is similar to the one that Westinghouse first put his air brakes on. Click for larger image. Woodbridge Township, NJ.