The detachment in London under Captain Owen was throughout the year, attached to the Commissioners for the Exhibition of 1851. Four of the party were generally in the office performing the duty of clerks and draughtsmen. Among the services executed by them was the organization and classification, for historic and scientific purposes, of the voluminous correspondence, documents, and tabulated forms and returns of the department, previous to their deposit in the royal archives. To this was added the duty of preparing the various certificates with the signature of Prince Albert, and forwarding them, with the exhibitors’ and jurors’ medals, and juries’ reports, to the different local and foreign committees throughout the world. To corporal Gardner was intrusted the office of stamping the Prince’s signature. Before he commenced the task he made some experiments to ascertain the best mode of transferring the royal name from the block to the paper. His object was to make the impression a perfect resemblance of the original, to accomplish which the use of common ink was a desideratum. Observation and ingenuity soon led him to adopt an expedient that proved to be very successful. About 20,000 of these certificates he prepared, and many of the transfers were such faithful fac-similes of the original, that the minutest examination of their details failed to discover the slightest deviation from the character of the royal autograph. For two or three months when the men were not employed on more pressing services, they were advantageously occupied in collecting and arranging specimens received from the exhibitors, now composing the trade collection at Kensington palace. They also examined and took charge of the Exhibition photographs, executed in Paris, 18,000 in number, after their return by Messrs. De la Rue and Co. who mounted them. In the evening after the day’s labour had ended, five of the party attended for four months the Government school of design at Somerset House, and received instruction in free-hand drawing. The privilege thus conceded was not only unprecedented but greatly enhanced by an instant departure from the rule of the institution, which required candidates to avail themselves of its benefits in their turn. By the end of the year the sappers with Captain Owen were reduced to four non-commissioned officers. In January and February two non-commissioned officers with six civilians as labourers, under Mr. John McLaren,[101] the deputy surveyor-general of South Australia, were employed in establishing an overland route from Adelaide to Mount Alexander. They laid out a line of road between these points through the wilderness, removed all striking obstructions, and formed at every practicable locality convenient wells of water for the use of travellers. The object of laying down this line of communication was principally to assist the transit of the “gold diggers” of the Mount and the contiguous country into Adelaide.