hold their first plenary session of ICO in conjunction with the next General Assembly of IUPAP in July 1948 in Amsterdam. (The Dutch delegate, Prof van Heel, invited the ICO to meet at his laboratory in Delft.) The organizers also formulated the objectives of ICO: the study of optical theory, the theoretical study and construction of optical instruments, and the physiological optics of the eye. The organizers were grateful to both UNESCO and IUPAP for travel, secretarial and publication support during the initial organizational stage, but in order to ensure smooth functioning of ICO in 1948 and beyond it was decided to assess each member country for an annual contribution based on the same population scale used by IUPAP: countries with less than 5 million inhabitants, 1 unit; 5 to 10 million, 2 units; 10 to 15 million, 3 units; 15 to 20 million, 5 units; and greater than 20 million, 8 units. As tasks to be accomplished in the near term by ICO, each national committee was asked to establish if possible a list of the names and addresses of its optics researchers and also a list of the manufacturers of optical instruments. Each country was also asked to supply a list of their optics publications for the war years 1939–1945. As a further challenge to the new organization the delegates compiled a list of about 20 technical problem areas in optics. These subjects were assigned to various ICO national committees, with a request that each committee report on its problem at the 1948 meeting in the Netherlands. Most of the problem areas represented the special interests of the delegates present at the preparatory session, and this would provide a quick mechanism to ensure some technical content at the first formal meeting of ICO. Italy (Giuliano Toraldo di Francia) would survey diffraction theory; Great Britain (T. Smith) would survey aberration studies (without diffraction); and France (André Maréchal) and the Netherlands would report on the combined effect of aberrations and diffraction. Sweden (E. Ingelstam) would survey gratings; Great Britain, photographic objectives; and other groups were assigned other tasks. Finally, there would be reports on sign conventions, notation, tolerances and the specification of optical drawings. In drawing up these assigned tasks the preparatory commission was following the usual format of a commission of a scientific union: stating specific problems to be reported on by the commission. In Prague the founding group