In later years, Telechron would advertise its clocks as "bringing true time," because power plants had begun to maintain frequency of the alternating current very close to an average of 60 Hz.

In order to overcome these problems, Warren invented a "master clock," which he installed at the Boston Edison Company in 1916.

[2] In Electrifying Time, Jim Linz writes that "in 1947, Warren Master Clocks regulated over 95 percent of the electric lines in the United States.

"[3] It is interesting to note, then, that the uniformity of alternating current in the United States, which was necessary in order to build large power grids, was initially ensured by a very traditional clock system.

[4] Rather, the Telechron company sought to produce clocks whose designs reflected one of the fundamental principles of the Art Deco movement: to combine modern engineering (including mass-production) with the beauty of simple geometric shapes.

As early as 1917, General Electric acquired a strong interest in Telechron, realizing the economic potential of Warren's invention.

In addition to its association with GE, Telechron cooperated closely with one of America's most famous makers of traditional clocks, the Herschede company.

Walter Herschede became interested in synchronous clocks in the 1920s, but did not want to risk the good name of his company by associating it too quickly with the new technology.

Battery-powered clocks have the obvious advantage of not depending on the proximity of a power outlet, and do not require the often somewhat unattractive electric cable.

The Ashland plant was closed in 1993, and a memorial to Henry E. Warren was dedicated in the center of the town, adorned with a reproduction of a Telechron.

[citation needed] From a commercial point of view, it was the increased durability of batteries as well as the invention of the quartz movement that proved fatal to Telechron.

From the point of view of the history of technology, however, another problem is more crucial: if the electric power grid is used as a system for the "distribution of time," as Warren himself wrote,[6] then, in the case of a power failure, the clocks stop, and the individual consumers' Telechrons lose their connection with the master clock (and, by implication, with the time provided by the Naval Observatory).

Warren, foreseeing this difficulty, provided his clocks with an "indicating device":[6] a red dot that would appear on the dial whenever the power failed.

This red dot alerted the consumer to the need to reset the clock (by obtaining the accurate time through the telephone, for example, or from a radio).