“Not exceeding 4 oz. in weight, 1d. For every additional 2 oz., ½d.” “Get that into your mind,” the Guide seems to say, “and you will find that you have mastered the most useful fact in the whole system.” There are, of course, numerous qualifications to this rule arising out of the necessities of the Service. We may admit that there are perhaps too many of these in the Post Office system, and that it might be in the end cheaper for the Department to take more risks, but we can certainly see a good reason for the following:— “No letter may exceed two feet in length, one foot in width, or one foot in depth.” But there is an exception even to this: the British Government has a way of contracting itself out of its own regulations, and official letters are carefully excluded from the application of this rule. The mere layman feels annoyed at this; he usually pictures the Government as a designing body which is always “on the make,” and has certainly not yet arrived at the truth that the State represents him even in small matters connected with Post Office revenue. Everybody knows a postcard can be sent for a halfpenny, but you will be wrong if you think this is because it is a small thing, and that the Post Office charges are in proportion to the size of an article. Indeed the Guide will tell you plainly that if you reduce the card in size below 4 by 2½ inches it will be treated as a letter. This does not seem logical to many plain Britons, who think that half a postcard ought naturally to be a farthing. They don't appreciate the difficulties arising out of the carriage of diminutive articles.