Graph theory originated in German speaking countries and there directed edges are called "Pfeil" which translates to "arrow", which makes sense, because arrows have distinguishable front end and rear end that resemble the source vertex and target vertex of directed edges.


Now I noticed that in English papers the term "arrow" seems to be less frequent than the term "arc". That seems a little strange because arcs have no clearly distinguishable ends (what would e.g. be the front end of the [Gateway Arch](https://en.wikipedia.org/wiki/Gateway_Arch) of St. Louis, Missouri and what would be its rear end?)



> 
> **Questions:**
> 
> 
> * what are the earliest English publications on digraphs and what term is used there "arrow" or "arc"?
> * If there was a change in terminology, when did it happen and what were the influential publications?
> 
> 
> 



Name for Directed Edges in Digraphs
It's probably not the first, but the 1956 paper of Ford and Fulkerson, ["Maximal Flow through a Network"](http://www.cs.yale.edu/homes/lans/readings/routing/ford-max_flow-1956.pdf) used "arcs". 


