OCR Text |
Show Standard Time The United States Naval observatory observa-tory has three standard clocks running run-ning Iu constant temperature vaults, electrically wound and sealed to keep the air pressure constant. Meridian circle observations of selected stars are taken regularly on clear nights, and from these observations the er-rorj er-rorj of standard clocks are determined. deter-mined. The observatory sends out lime signals. Correct time Is given over radio networks as a.a advertising advertis-ing device. |