On Babbages System of Mechanical Notation. 



113 



A uniform motion is represented by an inclined straight 

 line, inasmuch as the spaces passed over in each unit of time 

 are equal : — 



A crank motion which begins gradually, attains its greatest 

 velocity in the centre of its half-stroke, and ends also gradually, 

 is represented thus : — 



In fact the space passed over in any particular unit of time, is 

 represented by the difference of the ordinates at beginning and 

 ending of that unit. 



A glance therefore at the accompanying chart will show the 

 actual positions of all parts of the machine at any particular 

 tenth of a second during the whole six seconds. 



Thus, for example, it will be seen in the first line that the 

 inking rollers roll backward and forward by a crank motion (or 

 motion analogous to it) six times during a cycle. In the second 

 line it will be seen that the inking rollers rise uniformly, and 

 attain their highest level in three-tenths second ; then they 

 continue (rolling backward and forward, as the first line has 

 previous!} 7 informed us), for 1*1 seconds; they then uniformly de- 

 scend and ascend again (to change position of rollers) in 0*6 second, 

 continue at their highest level, inking the rollers for 0*6 second, 

 and then uniformly descend and spend the remainder of this 

 time, 3'0 seconds, in taking up fresh ink. 



I might go through all the lines in the same way, but as the 

 same principle applies, it is hardly necessary as a very little 

 study will render the matter quite plain. 



Thirdly. The uses to which this system is capable of being 

 applied are numberless, and seem to continually increase as one gets 



