The rates for printed matter had for a long period caused considerable confusion, and given rise to many complaints from members of the public. They were still determined according to the linear surface of the sheets, a method which was found to cause considerable embarrassment and difficulty in its practical application. To all other classes of postal traffic the more logical and more convenient principle of charge according to weight had already been applied, and in 1856 this principle was applied also to printed matter of all descriptions. Weight was made the basis of the charge, without reference to superficies or to distance, except that for political reasons the privilege of half-rates for newspapers circulating in the department in which they were published was continued.[367] The reduction of the actual rates made by this law was slight, and was estimated not to have any appreciable effect on the total revenue. In any case the question was "regarded less from the financial point of view than from the point of view of the satisfaction which it would give to the needs of commerce and industry and of private intercourse in general."[368] The new rate was 1 centime for each 10 grammes, with a minimum of 4 centimes for political, and 2 centimes for non-political newspapers. This reduction of rate, together with the reduction for other printed matter, for samples, and for commercial papers, resulted in a large increase in the number of bulky packets sent by post. In order to ensure prompt delivery, it was found necessary in Paris to separate to some extent the letter-post traffic from the traffic sent at the lower rates, and the principle of providing a separate staff of postmen for the delivery of newspapers, magazines, samples, etc., was introduced.[369] The application of this principle has since been extended, and the two kinds of traffic are now dealt with in Paris altogether separately, by separate staffs of officers. The newspaper rates were next revised in 1878. The discrimination between political and non-political newspapers was abolished, but the privilege accorded to local newspapers was continued. The new rates were:-- 1. Two centimes for the first 25 grammes and 1 centime for each further 25 grammes or fraction of 25 grammes for newspapers published in the departments of Seine and Seine-et-Oise and circulating outside the department where published; and for newspapers published in other departments and circulating outside the department where published and the adjacent departments. 2. One centime for the first 25 grammes and 1/2 centime for each additional 25 grammes or fraction of 25 grammes for newspapers published in the departments of Seine or Seine-et-Oise and circulating within the department where published.