Show time lost by finest official U S clock washington Amerl americas cas most timely clock clicks oft off the fleeting moments with a n variation ot of only one hundredth of a second a lay day enclosed in an airtight air tight chamber especially constructed to keep outside influences away from the governments master ter timekeeper the standard etan dard clock at at athe the bureau of standards which lial haa MIS fills small variation in time Is used as a yardstick for measuring time intervals at the bureau the clock Is electrically wound twice a minute its time la Is checked ench each lay day by comparison with the noon signal from tile the naval observatory which uses solar observations to set the ie nations time |