Plate numbers for SG21
1 to 15
The first delivery of perforated stamps was made on the 31st January, 1854, when 1,500 sheets of the One Penny value were sent to the storekeeper at Somerset House, followed by further supplies, the total, up to and including the 1st March, being 74,000 entire sheets. The perforation of the stamps being quite independent of Messrs. Perkins & Co.’s contract.
For eleven months the machines perforated 16 holes in the space of two centimetres, which was precisely the same gauge as that of Archer’s last machine; and each machine was capable of perforating 1,500 sheets per day, in batches of three at a time, and sub sequently, after the introduction of the steam machines, at the rate of 600 per hour, five sheets at a time. In this, and the subsequent gauge of 14, the pins when worn produced smaller holes than when new, and the punctures were less sharply defined. Several sheets superimposed were operated upon at one time, as stated above, and, with a worn set of pins, the effect on the lower sheets was a series of jagged punctures, only a small portion of the paper being actually cut away.
The 16-gauge perforation did not entirely disappear until 1858.