THE BRIDGE STABILIZED OSCILLATOR 591 



Application 



The bridge stabilized oscillator promises to become a useful tool in 

 many commercial fields as well as in certain purely scientific problems 

 such as time determination and physical and astronomical measure- 

 ment. It may be used either to increase the frequency precision in 

 applications where operating conditions are accurately controlled, or 

 else to make such control unnecessary, affording high stability in spite 

 of unfavorable conditions. 



An interesting application in the field of geophysics' has already been 

 made in the form of a "Crystal Chronometer." This chronometer 

 consists of a single-tube bridge oscillator, a frequency dividing circuit, 

 and a synchronous timing motor. It was recently loaned by Bell 

 Telephone Laboratories to the American Geophysical Union and was 

 used with the Meinesz gravity-measuring equipment on a submarine 

 gravity-survey expedition in the West Indies. Although operating 

 under somewhat adverse conditions of power supply, temperature, and 

 vibration, it was reported ^ to be more stable than any timing device 

 previously available, errors in the gravity measurements introduced 

 by the chronometer being negligibly small. 



^"Gravity Measurement on the U. S. S. Barracuda," M. Ewing, and "Crystal 

 Chronometer Time in Gravity Surveys," A. J. Hoskinson; pp. 66 and 77 resp., 

 Transactions of the American Geophysical Union, Part I, 1937. 



