From the 1st January 1875 a uniform rate of 5 pf. for local letters was introduced throughout the Imperial postal territory. The rate was irrespective of weight, but there was a maximum limit of 250 grammes. All other local packets (postcards, printed matter, and samples) were subject to the ordinary rates of postage. No special local rate was fixed for parcels: the lowest zone rate was payable, and was, of course, in effect a local rate. The general application of the new letter rate would, in certain cases, have resulted in increased rates, and in those cases (Constance, Darmstadt, and Karlsruhe) a rate of 3 pf.--the equivalent of the previously existing rate--was established. In Berlin, in view of the specially expensive arrangements for the delivery of letters, the rate of 10 pf. for local letters remained in force.[561] For the delivery of local parcels no charge had previously been made beyond the rate of local postage, although in respect of all packets from outside a delivery charge was collected. From the 1st January 1875, however, local parcels were made liable to a delivery charge.[562] In general, the local rates introduced on the 1st January 1875 remained for more than a quarter of a century unchanged, but in course of time difficulties in their administration developed. The order of the 18th December 1874 had prescribed a special local rate for letters only; for all other kinds of postal traffic the ordinary rates remained applicable. Consequently, a local postcard was charged the same postage as a letter weighing 250 grammes; similarly the rates for printed matter or samples for local delivery were high when compared with the rate for local letters. Such rates were, moreover, anomalous when compared with the rates for long-distance traffic, which, for postcards, printed matter, and samples, were much less than for letters. In fact, for local delivery printed matter and samples had only to be placed in sealed covers in order to pass at the rate of 5 pf. In many of the larger towns the delivery of local letters was undertaken by private enterprise at rates much lower than those of the Imperial Post Office. The undertakings secured a very large proportion of the local traffic, and found even these low rates very profitable. Moreover, the large increase in the number of post offices, and the withdrawal of numerous places from the areas assigned to certain offices, had led, in many cases, to great difficulties in deciding whether letters were subject to the general or the local rate of postage.[563]