“_Clause 1._—The Imperial Government shall grant to no other contractor, either individual or corporation, the right of constructing or working a railway line joining the said localities or liable to compete with the line ceded by the present decree or any parts of same.” “_Clause 9._—The Imperial Government guarantees to the German East African Railway Company, subject to compliance with the prescribed formalities, an exemption from all taxes on materials, engines, working tools, and all other implements and articles which may be imported into German East Africa for the construction, repair, renewal, and running of the railway.” In drawing up special tariffs with its concessionaire, it may be asked whether the State can base these rates on the actual working expenses—that is to say, with neither profit nor loss for the concessionaire. From an economic point of view, such a tariff is perfectly justifiable. Transporting operations, _per se_, cannot be separated from the transactions to which they are related. These transactions must be considered in view of all the surrounding circumstances. In negotiating transport operations, which of themselves entail neither profit nor loss, a contractor is quite justified in calculating on present or probable advantages which may result from the whole of the operation; as, for instance, the opening of new markets and the renunciation to the right of immediate repurchase of the concern. To forbid him to do this would be to spoil his chances and deprive him in many cases of a part of the profit to which he is justly entitled.