To-day, we are familiar with such phrases as "standardized parts" and "quantity production," which explain to us how it is possible for a single factory to produce millions of watches in a year, or for another kind of plant to turn out half a million automobiles in a like period. The way in which "quantity production" came about is curiously interesting. Watch-making received one of its greatest impulses from a famous American inventor who probably would have been amazed had anyone told him that his idea upon quite another subject would some day help to put watches into millions of pockets. There is no particular connection between a cotton-gin and the "quantity production" of watches, but it is interesting to know that the same ingenious brain which designed the one also unconsciously suggested the other. Late in the eighteenth century, Eli Whitney gained lasting fame as the inventor of a machine which would automatically separate the seeds from the fiber of crude cotton—a machine which revolutionized the cotton industry of the south. In 1798, Whitney secured a contract to manufacture rifles for the government. He decided that they could be made much more rapidly and cheaply if he could find some way to produce all the separate parts in large quantities by machinery, and then merely assemble the various parts into the completed weapon. The inventive mind which was capable of devising the cotton-gin found this new problem to be comparatively simple, and it was not long before Whitney was making thousands of rifles from machine-made "standardized parts," where only one could be made before. Half a century later his machinery was still turning out rifles parts in the great arsenal at Springfield, Massachusetts, and it was not until this period that it exerted a distinct influence upon watch-making. While Howard in Roxbury was dreaming of producing watches by machinery, another young man—Aaron L. Dennison, of Boston—was also obsessed with the same dream and grappling with the same problem. It is therefore not strange that the paths of these two soon crossed. Born in Freeport, Maine, 1812, Dennison was just a year older than Howard. He was an expert watch-repairer and watch-assembler, having learned his craft among the Swiss and the English workmen in New York and Boston. The year 1845 found him conducting a small watch and jewelry business in Boston. Some few years earlier, Dennison had visited friends in Springfield, Massachusetts, and while there he was taken to one of the interesting show-places of the town—the Springfield Arsenal. As he made his slow progress through the great rifle factory, he marveled at the wonderful machinery and the system which had originated in the brain of Eli Whitney nearly half a century before; Whitney was dead and gone, but his works still lived.