Definition of "peatman"

We hear of Adder dens, but detailed accounts of the discovery of one are very rare. Service (1902) records that a peatman, when levelling on an estate by the Solway, found in a hole in the ground, some 8 inches below the surface, 40 adders, 10 toads and a large number of asks (lizards).

1951, Malcolm Arthur Smith, The British Amphibians & Reptiles, page 258