d Kingdom the rates are:--

For a packet not exceeding 2 ounces in weight 1/2d.
" exceeding 2 ounces and not exceeding 5 lb. 1d.
" " 5 lb. " " 6 lb 2d.

It will be noted that the initial penny rate is maintained (the 2 ounces
for 1/2d. being merely the ordinary printed matter rate), but a
comparison with the ordinary parcel post rates (see Chapter III) will
show that if, as there is reason to believe, those rates are
unremunerative, the rates for literature for the blind must involve a
heavy loss on each packet. The number of packets is, however, only some
300,000 per annum.

Similar low rates are in operation in other countries. In the United
States packets containing matter of this kind are carried free.

* * * * *

(VI) MINOR RATES IN THE UNITED STATES AND CANADA

In the United States and Canada a special method of differentiating
rates of postage has been adopted. All postal traffic is termed "mail
matter," and is classified in four groups, to each of which is applied
an appropriate rate. The classification, which is almost identical in
the two countries, is based partly on the general character of the
packets (size, shape, etc.), but more largely on certain general
principles of administration, and on the intrinsic value of the
contents. Thus the ordinary letter, which is the most important and
valuable traffic, is placed in the first class of mail matter, and is
charged the highest rate. Newspapers and periodicals, which are regarded
as of great importance in aiding the education and enlightenment of the
people, are placed in the second class of mail matter and are given the
lowest rate.[527] Books and all other printed matter, commercial papers,
postcards, etc., are regarded as of less importance than letters, and
are deemed to be less entitled to encouragement from the State in their
distribution, but still entitled to preferential treatment as compared
with packets containing miscellaneous articles. They are accordingly
placed in the third class of mail matter, and are given a rate
intermediate between that of the first class and that of the second. All
other articles sent by post--the residuum of postal packets--are placed
together in a fourth class of mail matter, to which is applied a rate
higher than the third-class rate, but considerably lower than the
first-class rate.[528]

The rates for first-clas