The book made no references to the age of the machine but clearly shows wooden cogs and gears with wood pegs holding the timber frame together.

[*] A.
Beam or Helve
[*] B.
A trunnions which supports the beam.
[*] C.
The hammer face.
[*] D.
Anvil face.
[*] E.
Anvil.
[*] F.
Trunnions
[*] G.
A metal strip called a shell or striker plate.
[*] H.
The power shaft or axle and hub
[*] I.
The toothed wheel. This could be adjusted by additions of teeth to strike at certain intervals depending on the metal being worked X.