Japanese Post Office ‘√ 2 Square Package’ proof 1872
Baron Maejima Hisoka (前島 密, January 24, 1835 – April 27, 1919) visited Great Britain in 1870 to study the workings of the General Post Office, and upon his return to Japan the Japanese post office began operation in April 1871 with a daily service linking Tokyo with Osaka. Baron Maejima personally coined the Japanese word for postage stamp (kitte).
In Japanese language counter words or counters (josūshi 助数詞) are used along with numbers to count things. Depending on the form of an object different counter words are used. When devising the Japanese post office system consideration was given to calculating the fee in relation to the type of object being sent. This resulted in a test variation on the 200 sen stamp design of 1871 which was created for square letters and parcels, with the cost denominated as a measurement of the diagonal length across the item multiplied by a scale in sen value (a unit of money like the British pound or US dollar) value.
Given that a square of sides 1 x 1 has a root 2 (√ 2) diagonal measurement this was incorporated into the stamp value and can be seen printed in black in the centre. To further distinguish this issue from the standard 200 sen issue the proof displayed arranges the stamps in a sheet of 8 x 8, with those to the top left of the diagonal across the sheet printed upright, and those below the diagonal printed inversed, intended to assist the post office in selecting the correct postage stamp.
Unfortunately, it was realised that being an irrational number the root 2 would lead to complications in offering the correct change and this resulted in the stamp not being released. This is the only known copy of the original complete proof sheet.