000			005700000a22002050004500
245			_aFrom Sundials to atomic clocks : understanding time and frequency
100			_aJespersen, James
100			_aFitz-Randolph, Jane
100			_aRobb, John illus.
260			_aNew York _bDover Publications _c1982
300			_a175p. : ill.
440			_aNational Bureau of Standards monograph ; no. 155
500			_aIndex included
020			_a048624265X
080			_a681.11 _bJ4
650			_aTIME MEASUREMENT
650			_aCLOCKS
041			_aEN
942			_cBK
999			_c39980 _d39980