ONE of the great difficulties in exhibiting together samples of the produce and the industry of the world, must obviously be the magnitude and con .. sequent expense of any building capable of con· taining such an exposition. In order to do this most effectively, and to secure the greatest amount uf space for the primary object, it became necessary to lay down principles within the limits of which the objects exhibited should be confined. No real difficulty opposed the definition of this boundary, even if a liberal interpretation were admitted.