Editing Samuel Langley (section)

==Commercial time service==
Starting with his tenure at [[Allegheny Observatory]] in the [[Pittsburgh]] area in the late 1860s, Langley was a major player in the development of astronomically derived and regulated time distribution services in America through the later half of the 19th century. His work with the railroads in this area is often cited as central to the establishment of the [[Standard Time]] Zones system. His very successful and profitable time sales to the [[Pennsylvania Railroad]] stood out among the many non-government-based observatories of the day who were largely subsidizing their research by time-service sales to regional railroads and the cities they served. The [[United States Naval Observatory]]'s increasing dominance in this field threatened these regional observatories' livelihoods and Langley became a leader in efforts to preserve the viability of their commercial programs.