The Jewelers' Circular, October 1, 1919, pages 153, 155:
  Wireless  Equipment  for                   
the  Practical  Jeweler  

Written   Expressly   for   The   Circular   by   Eugene   Dynner

Fig. 1 Among the many disadvantages under which we were forced to labor during the long period of hostilities with Germany, was that of being prohibited from enjoying the valuable privilege of comparing our time pieces with the Naval Observatory's wireless time signals. Thanks to the cessation of the war and the Government's pleasure, we are again privileged to make use of this service. The official announcement of our Government that private parties might now proceed with the erection of radio receiving stations has aroused great interest among the watchmakers and jewelers of the entire country, for to all those concerned with the adjustment of watches it has long been no secret that the time signals as transmitted by radio were unquestionably superior to the old land line time signal systems--no matter from what angle of comparison.

Efficiency  Aspect

    In the ordinary telegraph wire, when a signal is transmitted it is not detected immediately at the receiving station, because the great expanse of wire offers quite an appreciable resistance to the passage of an electric current. This necessitates relays at several points on the route which are required in order to prevent the signal from dying out altogether. The mechanical action taking place in the relay added to the natural lag of the current in the circuit naturally causes a delay in the time signal. For ordinary purposes, such as the transmission of telegrams and time signals for common use, this service is sufficiently adequate. For comparison of fine time pieces, however, this is not quite satisfactory, as only a time signal which will be absolutely correct and invariable will serve the purpose. Such a time signal is offered by the radio service of the Navy Department in its radio stations on the coasts of the United States.

Speed  of  Radio  Signals

    Radio signals travel at the speed of 186,000 miles per second, or the speed of light, and until something that will transmit a signal faster is discovered, this will continue to be the most desirable form in which time signals will be available to those who require them.
    In the preface to his exhaustive treatise on the performance of various watches--"Watch Tests" is the title of the book--F. M. Bookwalter of Springfield, O., says: "The Naval Observatory . . . has recently added a new reliable and efficient service in its Arlington wireless station, for these time signals. Any person can erect a receiving station for these wireless signals, and may enjoy their benefit without fee or license. The writer sometime ago erected and equipped a radio station at his residence, which receives the Arlington radio time signals. This method is therefore more convenient and pleasurable than the telegraph signals which he formerly used." And again: "The absolutely reliable radio time service of the Washington Observatory affords convenient opportunity to compare the service of watches with an unquestioned standard. The five-minute service enables the critic to compare a number of pieces at the end of each half-minute and each minute. A more reliable average performance of any particular grade can thereby be obtained than when only one or two watches on different occasions and under different circumstances are handled."
    A reproduction of one of Mr. Bookwalter's wonderful charts is appended herewith. Note that the time standard of comparison for these extremely accurate observations is the Arlington time signal. The superiority of the wireless signals from the point of accuracy having been established, we may now take into consideration the financial end of the business.

Comparison  to  Land-Line  Systems

    Consider the installation of a wire system of time signals. The service as rendered at present is quite costly, because the return on the rental of the clock is insignificant when fine watches are considered, as invariably the watch may be depended upon to keep better time than the signal. Dependence upon the signal may often cause placing a fully adjusted watch out of position, therefore causing much trouble. And if the service is undependable, why pay for it? And if one pays for nothing he entails a financial loss. A wire time service is therefore a loss rather than an investment. The wireless time signal, on the other hand, may be depended on for absolute accuracy, and the cost is only initial--the upkeep being generally nil in the case of a crystal detector being employed. This matter will be covered later.