"I am working," said he, "for a company which makes seven complete watches in a day." Great was the merriment at this reply. "Why, where on earth could you _sell_ seven watches a day?" they shouted. With the advent of the factory, the real troubles of Dennison and Howard began. It is worth while to glance for a moment at the problem which lay before them, if only to appreciate its difficulty. The old plan was to have a model watch made by hand by a master workman. This watch was then taken apart and its separate parts distributed for reproduction by a multitude of specialized workers involving perhaps some forty or fifty minor trades. These parts, hand-made after a hand-made model, were then returned to the expert who assembled and adjusted them. At the worst, this resulted in gross error; at the best, in individual variation. A part from one watch could not be expected to fit and work accurately in another, although the two were supposed to be alike in all their parts. The new idea was first to lay out the whole design on paper and then to make the various parts by machinery according to the exact design. It was supposed that a machine making one part would duplicate that part repeatedly without variation; that in so far as the machines themselves were accurate, the parts produced would necessarily be interchangeable; that any set of parts could therefore be assembled without fitting or alteration. The finished watch, it was assumed, would require adjustment only. Theoretically, this idea was correct; practically, it could not be perfectly carried out, and the results did not fulfil the hopes of the manufacturers. In the first place, there were not in existence any machines of the required delicacy and precision; every one must first be invented, then designed, then made, and finally adjusted for practical operation. Even so, and notwithstanding the great mechanical achievements of the Waltham Company, the results never succeeded in realizing the dreams of Howard and Dennison, of absolute interchangeability of parts. It remained for the Ingersoll organization, many years later, to develop such a factory system. Before Howard and Dennison could make a single watch, therefore, they had to invent all the mechanism, and themselves build and install every invention. Moreover, several of the processes had to be worked out from the ground up. There was nobody in America who understood watch-gilding, for example, or who could make dials or jewels.