The general idea of this shop was taken from the nave and side aisles of Gothic cathedrals. The central and wider portion, which we may call the nave, was one story in height and was commanded by the travelers, and its floor was occupied by the largest tools only, and for erection. The side aisles were two stories in height. The smallest work, of course, was on the upper story, and tools and work of medium size on the floors below, the latter being transported by carriages suspended from the floor above. No rails were laid or gangways kept open on any floor. All transportation of heavy objects was through the air. The great value of this improvement, made by this firm in shop design, and which has brought this design into general use, lay in its natural classification of the work. Travelers were already quite common in England, but under them large and small tools, often very small ones, were found mingled quite promiscuously. Their shop had an entire glass roof, made on the ridge and furrow plan, first used in the Crystal Palace in Hyde Park for the International Exhibition of 1851. That roof would not answer, however, in this climate, on account of our snow in winter, so I had to plan a different one. But in every other respect their plan was perfect. The columns, of course, at that time were of cast iron. These were cast in pairs connected by a web, the longer columns in each pair supporting the roof, the short ones the rails for the travelers. In Smith & Coventry’s shop the traveler was operated from the floor by means of a loop hanging from a wheel on the crab. The arrangement was exceedingly convenient in every respect.