Britain started her series of hydrogen bomb tests yesterday with an explosion high in the air over the Central Pacific. News of the explosion reached Mr. Jones, Minister of Supply, from Air Vice-Marshal W. E. Oulton, commanding the task force, and Mr. / W. R. J. Cook, scientific director of the tests.

The" device" was dropped from a Valiant four engined jet bomber. The Ministry announcement last night said that scientific records were still being collected. A further statement is to be made later.

No indication of the nature of the explosion was given. The statement merely referred to a" nuclear device." The term" device" indicates that it was experimental and not a fully developed weapon.

The term" nuclear" is used to include everything deriving its energy from a nuclear reaction.
They might range from a small tactical atomic weapon depending on fission of heavy elements like