Record #6 - Samuel Langley Letter on Allegheny Time System
Railroads have had a crucial impact on much of Pittsburgh’s history. Along with a series of canals, the Allegheny Portage Railroad connected the city with Philadelphia and other points east of the Appalachian Mountains to quickly move passengers and goods across Pennsylvania. This system was rendered obsolete by the Pennsylvania Railroad which constructed a direct rail line across the state in the 1850s.
The Civil War showed the importance of the rail system throughout the country and with the development of a transcontinental network the demand for new rails skyrocketed. Western Pennsylvania’s iron mills, several of which affiliated with railroad man Andrew Carnegie, took up the task of producing these rails. Once the Bessemer method of producing steel was implemented by Carnegie at the Edgar Thomson Works (named for the PRR president), affordable and more durable steel rails further facilitated railroad expansion.
Langley letter explaining that his was the first observatory to offer a railroad time service, July 3, 1885, Allegheny Observatory Records, UA.5.1
An extensive railroad network managed by hundreds of private companies produced myriad problems, many of which jeopardized safety. For example, each railroad kept its own time which could vary by as much as 15 minutes from company to company. With multiple companies using the same stretch of rails, too great a discrepancy in time could result in accidents; therefore, there was a real need to identify a method of synchronizing all railroads to a standardized time to decrease the number of collisions, saving lives and money in the process.
Original Allegheny Observatory, c.1886, Allegheny Observatory Records, UA.5.1
Samuel Pierpont Langley, Director of the Allegheny Observatory in Allegheny City, realized the answer. Langley discovered a way to obtain accurate time by using the telescope and positions of the stars. He began to make accurate time available to Pittsburgh, City Hall, and local railroads via telegraph. In 1869 Langley devised and made operational the electric system of transmitting telegraphic time to several of the Pennsylvania Railroad lines which were associated with the observatory. By subscribing to Langley’s service, companies could now literally buy time, and the money earned through the Allegheny System service funded the work of the observatory for many years.
By 1870, the Allegheny Observatory service extended over 2,500 miles with 300 telegraph offices receiving time signals. On November 18, 1883, the observatory transmitted a signal on telegraph lines operated by railroads in Canada and the United States. The signal marked Noon, Eastern Standard Time, and railroads across the continent synchronized their schedules based on this signal, marking the first day of railroad standard time in North America that is still used today. The U.S. Naval Observatory also used the Allegheny System to supply the correct time to the nation until 1920 when it began to offer its own time services free of charge.
Excerpt of New York Times article describing the shift to standard time, November 19, 1883.
The records of the Allegheny Observatory, now part of the University of Pittsburgh, include several letters from Langley describing the Allegheny Time service and the method by which it was transmitted. While his work revolutionized time not just for the railroad companies, but eventually for the United States in general, Langley was also studying the sun and experimenting in aeronautics. Information concerning the work of Langley and others at the Allegheny Observatory is outlined in the collection’s finding guide.
Pittsburgh certainly made its mark on the railroad industry with George Westinghouse’s air brake and signaling systems, steel rail production, and labor relations, but perhaps no innovation had as much of a practical and widespread impact as that of Allegheny Observatory’s standardized time service.
- Zach Brodt
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