A double file of giant transmission lines carrying the enormous load of 275,000 volts marches across the desert and mountains from the great power plants at Boulder Dam to the City of Los Angeles.
    The 266-mile line brings vast reserves of low-cost power to serve the homes and industries of Los Angeles, delivered at a frequency of 60 cycles, replacing the former 50-cycle electricity serving the quarter million meters on the lines of the city-owned Bureau of  Power and Light.
    With the delivery of Boulder Dam power to Los Angeles, the citizen-owned utility faced the problem of adapting consumers' equipment for satisfactory operation at the higher frequency.
    The job is now completed and stands as one of the year's outstanding examples of efficiency.  Without cost for adjustment and without major inconvenience to consumers, the change in frequency has been completed.  Thousands of different items of household and industrial electrical equipment, ranging from barber poles and hair clippers to 750-horsepower motors in industrial plants, have been adapted for operation on Boulder Dam's 60-cycle power.
    Chief among the many complex problems now smoothly solved, and most interesting from the standpoint of the man on the street, was the job of caring for more than 100,000 synchronous electric clocks.  Los Angeles' clocks kept time on a 50-cycle electric--but with the change to 60-cycles each 50-cycle clock would speed up, gaining 12 minutes in each hour.

    Twenty-five years ago a graduate of the Massachsetts Institute of Technology, Mr. Henry E. Warren, developed a clock designed to use for its ordinary household alternating current.  It was hard to sell a synchronous clock in those days because little irregularities in the speed of the powerhouse generators would put the clocks as much as five or ten minutes ahead or behind.  Mr. Warren soon solved this problem, however, by constructing a Telechron Master Clock to be installed at the power house itself.  This master clock contains a specially constructed clock movement which is checked regularly with the Naval Observatory Time Signals.  Whenever an irregularity in the number of cycles per second (frequency) occurs, an adjustment is made to speed up or slow down the generators which cause the frequency to to return to the correct speed and the clocks to the correct time.  It is rare, however, that the variation goes beyond a few seconds.  Today practically every electric company has one of these Telechron Master clocks governing the speed of its generators.
    From this invention have sprung not only the familiar electric clocks now manufactured by a score of firms throughout the country, but a host of industrial instruments--devices that turn heat on and off automatically, determine the length of time a vat of beer will brew, switch on and off the all-too familiar traffic light and many others.
    While the majority of alternating-current devices, such as radios, vacuum cleaners, fans, heaters, toasters, electric ranges, etc., would be unaffected by the cycle change, those relying on a cycle as a measure of time would be put sadly askew.  Foremost among these, of course, were the electric clocks.
    After careful study of the situation, the city's Bureau of Power and Light it would be its policy that no one should be allowed to suffer  because of the change.  The Bureau, therefore, begain a survey of its 285,000 meters to check up on the number of applicances on its lines that would be affected.  The company found that its consumers owned nearly 125,000 electric clocks that based their time-telling on a frequency of 50 cycles.
 
 

    Following its decision that it would change over all equipment without charge to the consumer, the Bureau of Power and Light proceeded to make preparations for the job of adjusting 125,000 electric clocks.  The problem was made especially complex by the fact that the utility discovered more than 250 makes of electric clocks with almost as many methods of constructon and gearing.  It was also learned that the manufactures of almost 200 brands were no longer making clock parts and had abandoned the business entirely.  For many of the obsolete models it was impossible to find substitute parts.  The Bureau contracted with a leading firm of clock experts, the E.W. Reynolds Company, for the making of clock adjustments.  So immense was the task that it was necessary to equip a three-story building containing over 80,000 square-feet of space for the extensive job of collecting, inspecting and repairing all clocks.
    The Los Angeles territory was divided into twelve districts, each with nine to nineteen district depots.  Owners of synchrous electric appliances were notified and requested to bring their clocks and motors to the neighborhood depot.  There the clocks were carefully checked as to condition and then sent to the central depot.  From there the readjusted clocks, cleaned by compressed air, given a special oiling, tested and guaranteed to run satisfactorily for 60 days, would be returned to the householder within five days.  It was soon found that the task of resynchronizing the clocks was in a great many cases so difficult that the only solution was the substitution of an entirely new rotor.  The Bureau, therefore, contracted with the pioneer Warren Telechron Company in Ashland, Massachusetts for approximately 50,000 clock rotors designed to operate on 60-cycle current.  These units in most cases were connected with the works of the consumer's clock with a minimum of effort.
    In many instances owners of 50-cycle clocks accepted the Power Bureau's alternate offer; instead of free cycle adjustment, consumers were offered a choice of several 60-cycle manual starting clocks--in even exchange for old 50-cycle clocks.
    One of the results of the operation has been the hiring of  75 special clock repair experts and many other men to handle stockroom detail.
    Everything connected with the Boulder Dam Development seems to be modeled on a gigantic scale.  The huge 275, 000 volt load is transmitted over special hollow copper conductor tubes.  Cars carrying equipment have had to be shunted and zigzagged from one railroad to another so as to find tunnels and bridges of sufficient size.  Unquestionably, too, the change-over between 100,000 and 125,000 clocks without charge to the owner has been an operation of unprecedented scale.
    Today the job is done and Los Angeles is being served by Boulder Dam power--delivered in Los Angeles only after the facing and solving of many difficult and complex problems, one of which was the cycle changing of consumers' equipment without cost and with minimum inconvenience.