188 [Assembly 



The article called a cam has become a familiar name to a modern 

 machinist, to express a facility device or thing, in the construction 

 of various machines of the utmost importance to their existence, ef- 

 fecting and performing the manipulations of the human hand in giv- 

 ing expeditious action to the same; and by the aid of which have 

 started into being, in this country and in Europe, machines which 

 perform an amount of labor, estimated equal to that of six millions 

 of men; or, in other words, the withdrawing of which device from 

 such machinery, would put a stop to their motions, and in many of 

 them no other movement, or facility could be substituted in their 

 place. 



With this auxiliary to mechanical invention we overleap time and 

 space, as it relates to the slow system of apprenticeship in trades, as 

 practiced by our forefathers; for with a full knowledge of the qual- 

 ities and combinations of the cam, a mechanical engineer is never 

 at a loss for any motion required in the execution of his projected 

 machine. He can sit down and draft a plan of a machine having, 

 if need be, fifty distinct motions, in the space of a single week, and 

 in the farther space of a few weeks more, have a machine built and 

 put in operation, which will be capable of turning out a better and 

 more uniform article, than can possibly be done by an apprentice to 

 the trade, after a seven years apprenticeship; and having perhaps 

 the farther advantage of making 50 or 100 to one over the hand me- 

 thod of doing it. Cams may, therefore, be called America's " ap- 

 prentice boys." 



An article whose importance is of such magnitude, possessing such 

 general traits of character — traits as easily recognised by the practical 

 machinist as those of the screw, wedge, lever,or wheel, should also have 

 a name and a place in our dictionaries corresponding with its vast im- 

 portance. No standard work has given to it a critical definition 

 and meaning. Dr. Ure has omitted it entirely in his valuable dic- 

 tionary of the arts, notwithstanding he makes use of the w^ord pro- 

 bably five hundred times, in the description of machines contained in 

 the work itself; and the desire appears to be universal among the 

 better informed mechanics of this country, to see it placed and pro- 

 perly defined on the pages of some standard dictionary, to be copied 

 in all succeeding time, as the thing cf all work in the mechanic 

 arts. 



We therefore venture the remark, that the cam, well understood, 

 in the hands of American genius, aided by the energeis of the steam 



