The book post, instituted in 1848, had its rates reduced in 1855 and again in 1870 to a halfpenny for the initial two ounces and an additional 1/2_d._ for each succeeding two ounces. In 1892 its scope was greatly enlarged and the expression Halfpenny Post, which is now its official name, better illustrates its cosmopolitan character for it now includes all printed documents of a conventional, formal, or impersonal character. From 1872 to 1875 the number of articles carried by the Halfpenny or Book Post increased from 114 millions to 158 millions. The yearly average during the next five years was 204 millions; during the following five, 305 millions and for the five year period ending March 31, 1891, they had increased to 418 millions. During the next five years there was a still greater average increase to 596 millions and the average for the postal year ending in March, 1901, was 732 millions.[281] The rates for the Inland Pattern and Sample Post, established in 1863, were assimilated with those of the Book Post in 1870. It was abolished or rather incorporated with the Letter Post in the following year but was reëstablished in 1887, the rates being a penny for the first four ounces and 1/2_d._ for each succeeding two ounces, but, when the Jubilee letter rates were published, it lost its _raison d'être_ and was abolished for inland purposes.[282] [281] _Rep. P. G._, 1896, p. 2; 1903, p. 5; 1904, p. 5; 1881, app., p. 12; 1891, app., p. 17; 1901, app., p. 27. [282] _Ibid._, 1864, p. 29; 1896, p. 2; _Acct. & P._, 1871, xxxvii (pp. 1-2). Post cards were introduced in 1870, being carried for 1/2_d._ each prepaid, 2_d._ when payment was made on delivery.[283] In addition to the stamp a charge was made to cover the cost of the material in the card itself. Somewhat later reply post cards were issued for the inland service and arrangements were made for the use of international reply post cards. In 1894, private post cards, to which a halfpenny stamp was affixed, were allowed to pass by post. The resulting enormous growth[284] in their number showed that the privilege was appreciated. In less than five years they were estimated to form 5 per cent of the total number passing through the post.[285] Shortly after, the prohibition of any writing save the address on the face of a post card was withdrawn and it was provided that the address side of all mail matter might be used for purposes of correspondence provided that it did not obscure the address, encroach upon the stamp, or prove in any way inconvenient. Formerly, so far as mail matter other than post cards was concerned, the right half of the face side was reserved for the address.[286] During the four five-year periods from 1881 to the year ending 31st March, 1901, the average numbers of post cards delivered yearly in the United Kingdom were about 108 millions, 152 millions, 272 millions, and 379 millions.[287] [283] Charge on unpaid inland post cards reduced to 1_d._ each in 1896.