dialer

noun2

1. •
   A person or device that dials, as using a telephone.

   • He treated his assistant as a voice-operated dialer.
2. •
   A mining surveyor.

   • […] let the dialler, with the same instrument he uses underground, run a north and south line on the surface, in any convenient part of the sett, marking the extremities by well-fixed points, […] — 1857