§ 11. Mr. Partridgeasked the Parliamentary Secretary to the Ministry of Works, as representing the Lord President of the Council, to what extent research at the National Physical Laboratory has shown that the earth is rotating irregularly.
§ Mr. H. NichollsMeasurements to an accuracy of one second in three hundred years have been carried out at the National Physical Laboratory, on the so-called "atomic clock"; and these, when compared with astronomical measurements of time, show that the earth turns slightly faster during our summer and slower during our winter. A summer's day is about one thousandth of a second shorter than a day in mid-winter. Moreover, it appears that the earth has been slowing down for several years. There are now indications, however, that the earth is speeding up again.
§ Mr. PartridgeWhile commenting what a delightful reply that was, may I ask my hon. Friend how much scientific manpower is used to acquire the information and provide the material for his wonderful Answer; what use is it, and why do we bother with it?
§ Mr. NichollsThe work on the "atomic clock" takes the time of four men, two scientists and two assistants. 182 The National Physical Laboratory is responsible in this country for our basic standards, and it must be capable of providing standards of measurement to an accuracy sufficient for the requirements of scientists and engineers. I suppose that means that if the laboratory is proposing to give information on which time has to be based, it must be accurate so far as the laboratory can make it.