A discussion on units and standards

The sequence of papers following, contributed by members of the staff of the National Physical Laboratory, gives an account of most of the units and standards which are studied at the Laboratory. Each paper explains briefly the principal technical points involved, together with a short history. Of necessity a standard is to some extent a convention, and it may therefore be well to introduce the subject by a short review of the legal and conventional authorities on which they depend. For the metric system the main international authority is the Conference Generale des oids et Mesures, at which duly accredited delegates of each of the thirty-two nations subscribing to the 1875 Treaty, the Convention du Metre, are present, and which, in normal circumstances, meets every six years. The Comite International des Poids et Mesures is the Executive body appointed by the Conference Generale to manage the affairs of the Bureau International des Poids et Mesures between meetings of the Conference Generale. It consists of eighteen members, elected by the Conference, each of whom must belong to a different State, but who, as members of the Committee, are no longer representatives only of their individual countries, but of all subscribing countries. The International Committee meets every two years, makes recommendations to the General Conference, or acts on authority delegated to it by the Conference.