Why do blacksmiths tap their anvils with lighter tap taps while working? This is not to call a striker, those signals have already been discussed in another thread.
During forging the blacksmith will hit the metal something like BLOW, BLOW, BLOW, tap, tap.
They sometimes even hit the anvil with the hammer (no metal) several times.
When I researched it on the net it was suggested to rest the arm, keep rhythm, try to buy time and figure what to do next, etc.
I did find a quote by Frank Turley - "Three R's" rest, rhythm and rumination.
What are the real reasons? Is it even necessary to tap the anvil while forging?