The new locks were machines of the most delicate kind, the action of which depended in a great measure upon the precision with which the springs, sliders, levers, barrels, and other parts were finished. The merits of the invention being generally admitted, there was a considerable demand for the locks, and the necessity thus arose for inventing a series of original machine-tools to enable them to be manufactured in sufficient quantities to meet the demand. It is probable, indeed, that, but for the contrivance of such tools, the lock could never have come in to general use, as the skill of hand-workmen, no matter how experienced, could not have been relied upon for turning out the article with that degree of accuracy and finish in all the parts which was indispensable for its proper action. In conducting the manufacture throughout, Bramah was greatly assisted by Henry Maudslay, his foreman, to whom he was in no small degree indebted for the contrivance of those tool-machines which enabled him to carry on the business of lock-making with advantage and profit.