The Universal Postal Union as at first constituted provided only for the transmission of what may be regarded in the broad sense as letter post traffic. It made no provision for the transmission in the international service of packages of ordinary merchandise. Such packets could in strictness only be forwarded at the letter rate, which was almost prohibitive; although frequently they were forwarded at the sample rate, in which case the weight of the packet was strictly limited. The French administration proposed, in the project of the Congress of Paris of 1878, to extend in that direction the facilities provided by the Union, by amplifying the definition of samples to include small parcels of ordinary goods,[599] a proposal which was rejected by a majority of the administrations. It was, however, submitted to the Congress under another form. The German administration proposed, not the extension of the sample privilege, but the establishment of a new service, which should provide for the transmission of parcels of general merchandise not exceeding 3 kilogrammes in weight, the parcels to be charged a rate of postage sufficient to reimburse the administrations for the expenses of transmission. Although this proposal was favourably received, many of the delegates had no power to enter into any arrangement of that nature. The question was therefore referred to the International Bureau, with instructions to call a special Conference for its consideration, if on investigation that course should be found desirable. At this time the circumstances in the different countries in regard to the transmission of small parcels varied. In some a service was provided by the Post Office; in others, the majority, the business was left to the railways or other forms of commercial transport. In all cases the services between different countries were regulated by conventions and agreements on such terms as could be mutually arranged between the contracting parties. In general the rates of postage were based on the rates for inland transmission in each of the countries concerned. They were often extremely complicated, and several administrations had mutually agreed to a uniform rate for parcels not exceeding 5 kilogrammes in weight.