The advantage of having an easy method of separating the stamps were first brought to the notice of the Government by Henry Archer, and Irish London businessman. He submitted his plan to the Postmaster-General by whom it was passed on through various channels and experiments until finally approved. Archer’s patents were copyrights purchased for £4,000 in June 1853 following the success of the Prince Consort Trials. New machines (gauge 16) were constructed by David Napier & Sons. After their installation in Somerset House trials were carried out before official perforating finally became standard procedure. All the experiments and trials are traceable in stamps - insofar as they have survived. These stamps fall into three groups :

Early Archer Experiments with the two rouletting machines.
Both were failures, but of one a few stamps have survived (SG16a), rouletted about 11½ (generally referred to as "12")

Trials on Henry Archer’s third machine.
The first to be based on the perforating, as distinct from the rouletting method. The machine proved very unsatisfactory at first but after extensive repairs and alteration it was finally approved. The stamps which resulted from the trials were generally issued and are known used in different parts of the country - many went to the West of England.