This abuse of the privilege is, however, confined to a comparatively small proportion of the newspapers entitled to transmission at the newspaper rate. With the fall in the price of paper, and the improvements in printing methods and machinery, all newspapers have tended to increase in size. But in general the increase has been small. In 1855 the average weight of newspapers passing by post was 3·1 ounces,[303] and in 1913 it had increased to 4·1 ounces. The number of papers entitled to the privilege which could be regarded as excessively heavy is not more than about 50 (out of a total of some 2,200),[304] and although practically all these papers are published in London, and are largely distributed through the post, they do not form more than a small proportion of the total number of packets passing by newspaper post. But such of these publications of vast bulk and weight as are sent at the newspaper rate derive a great advantage--an advantage measured by the heavy loss incurred by the Post Office in respect of each such publication.[305] Many of the moderately heavy papers, such as the ordinary sixpenny London newspapers, are for the most part in compliance both with the letter and the spirit of the regulations, and their transmission at the 1/2d. rate is not, perhaps, open to serious objection. But there can be little doubt that if the possibility of developments in the publication of trade journals such as have occurred, had been foreseen, some provision would have been made for the prevention of the transmission at heavy loss to the Post Office of large numbers of publications which are, in effect, trade catalogues. While the newspaper post involves a very considerable loss, it affords the public a useful facility, and one which is largely availed of for the purpose the Act of 1870 was intended to assist, viz. the dissemination of intelligence.[306]