Operation Totem Cockcroft, the director of the Atomic Weapons Research Establishment at Harwell personally lodged a formal request for a feasibility study with the Prime Minister of Australia, Robert Menzies, at a meeting on 4 September 1952. Other matters discussed included the attendance of Butement and Leslie Martin, the Australian Defence Scientific Adviser, as Australian observers at the Hurricane test, the creation of the Australian Atomic Energy Commission, and the supply of Australian uranium to the UK. Cockcroft reported to Sir Roger Makins at the Foreign Office that Menzies had agreed in principle to Penney's reconnaissance of the Emu Field site. Penney
Atomic clock of using atomic transitions to measure time was suggested by Lord Kelvin in 1879. Magnetic resonance, developed in the 1930s by Isidor Rabi, became the practical method for doing this. In 1945, Rabi first publicly suggested that atomic beam magnetic resonance might be used as the basis of a clock. The first atomic clock was an ammonia absorption line device at 23870.1 MHz built in 1949 at the U.S. National Bureau of Standards (NBS, now NIST). It was less accurate than existing quartz clocks, but served to demonstrate the concept. The first accurate atomic clock, a caesium standard based on