2 58 Mr. Babbage on a method of expressing 
When it is thought requisite to enter into this minute detail 
of adjustments, it will be necessary, in order to avoid con- 
fusion, to put the lines indicating the order of adjustment, 
above and distinct from these signs. 
The last and most essential circumstance to be represented, 
is the succession of the movements which take place in the 
working of the machine. Almost all machinery, after a cer- 
tain number of successive operations, recommences the same 
course which it had just completed, and the work which it 
performs usually consists of a multitude of repetitions of the 
same course of particular motions. 
It is one of the great objects of the notation I am now ex- 
plaining, to point out a method by which, at any instant of 
time in this course or cycle of operations of any machine, we 
may know the state of motion or rest of every particular 
part ; to present a picture by which we may, on inspection, 
see not only the motion at that moment of time, but the 
whole history of its movements, as well as that of all the 
cotemporaneous changes from the beginning of the cycle. 
In order to accomplish this, each of the vertical indicating 
lines representing any part of the machine, has, adjacent to 
it, other lines drawn in the same direction : these accompa- 
nying lines denote the state of motion or rest of the part to 
which they refer, according to the following rules. 
| 1. Unbroken lines indicate motion. 
| 2. Lines on the right side indicate that the motion is 
from right to left. 
j 3 - Lines on the left side indicate that the direction of 
the motion is from left to right. 
