364 Mr. BappacE on the Influence of Signs 
namely, Italics, whilst the Greek letters are reserved for lines ; 
perhaps it might still be improved by interchanging these signi- 
fications of the two alphabets. 
Before I pass on to the consideration of the second species of sym- 
metry, I shall select from the Arithmetica Universalis, an example, 
in which the choice of the letters employed seems to have been 
made without any rule; and shall subjoin to it, the same problem 
expressed in a language consistent with the views I am illustrating. 
This course will render more apparent the advantages of attending 
even to the letters which we select to represent the quantities. 
“The velocities of two moving bodies 4 and B being given, and 
also their distance, and the difference of the times of the com- 
mencement of their motion, to determine the point in which they 
will meet. 
Let 4 have such a velocity that it will pass over the space ¢ in 
the time /; and Jet B have such that it will pass over the space d 
in the time g, and let the interval between the two bodies be e, 
and that of the times when they begin to move be h. 
CaselI. Then if both move in the same direction, and if 4 is 
farther distant from the point of meeting, call that distance x, from 
this take away the interval e, and there will remain x-e for the 
distance of B, from the same point. And since 4 passes over the 
space c in the time f, the time in which it will pass over the space 
» will be“. 
And so also, since B passes over the space d in the time g, 
the time in which it will pass over the space z-e, will be oe 
Now since the difference of these is supposed to be x, in order 
that they may become equal, add / to the smaller time; namely, 
fe. 
to the time ae (if B moved first) and it will become 
