In July and August of this year Canada is hosting four international organization concerned with the exploration and development of the earth and man's activities on the planet. More than 15,000 delegates from some 125 countries will take part in various activities of the 22nd International Geographical Congress, the 24th International Geological Congress, the 6th International Conference of the International Cartographic Association and the 12th Congress of the International Society of Photogrammetry, the major assemblies of which are being held in Montreal and Ottawa. The presence in Canada of these four international organizations gives implicit recognition to the work of Canadians in the field of earth sciences. The release of four appropriate Canada Post Office stamps, each with a denominative value suitable for use on mail destined for a large part of the earth's surface, provides evidence of the significance attached to these events in the host country. The Geology stamp illustrates a cross-section of the crust of the earth, showing different layers of material. It is anticipated that the 24th International Geological Congress will be the largest geological meeting ever held. The intense interest that it has generated may stem from the existence in Canada of a wide spectrum of geological features and phenomena. Another, but none-the-less important factor is world recognition of accomplishments by Canadian geologists is government, industry and educational institutes.