Two men were employed during the erection of the building in testing the cast-iron girders and columns with an hydraulic press, &c., and in ascertaining that all the bolts were sufficiently screwed up; also in keeping a record of the ironwork fixed each day. This duty was intrusted to lance-corporals Robert Fleming and Joseph Barrow; the former tested the girders, and the latter the proper adjustment of the fitments and bolts. In cases of dispute about the practicable application of some defective columns and girders, the opinion of corporal Fleming was, on three or four occasions, sought for; and he gave it in so clear and manly a manner, that his views were readily followed by the contractors. It is not a little remarkable that this non-commissioned officer was the only sapper recommended by Sir William Reid for promotion, during the period that the Colonel commanded the corps at the Exhibition. Corporal Barrow, when not employed in examining the fitments, took his place in the drawing-room, and notwithstanding the rough occupation he had been accustomed to, was found efficient. For the successful stability of the building, some little credit is at least due to these two humble officials. Their exertions were very great, and their vigilance in the important work intrusted to them was fully equal to the responsibility. Soon after the building was constructed, and before the goods began to be deposited, it was considered desirable to ascertain the effect of regular oscillation in the galleries. Experiments of different kinds were tried, but to carry out that which was regarded as the most trying, a strong detachment of the corps in close columns, keeping military time and step, was marched several times up and down, and round, and finally were made to mark time. With the result of this last test the eminent scientific men present expressed themselves highly gratified, and the incident was considered to be sufficiently interesting to become the subject of illustration in a popular journal.[78] Lance-corporal Charles W. Fear made, in the early part of the arrangements, a model of a portion of the building for the information of the Royal Commissioners, and afterwards was employed in making small models of counters of various parts of the building and other things of the kind required during the progress of the work. After the opening of the Exhibition a party was employed in repairing damages caused to the railings, counters, &c., and in copying, in model, some of the simplest and most instructive mechanical inventions and appliances for provincial institutions. The better to carry out the new style of constructing models, four of the party attended lectures on the subject delivered by Professor Cowper at King’s College, Somerset House.