Definition of "coalheaver"

...but rheumatism is a vulgar complaint, and would sink even a ducal coronet—the very lowest people have it. I question if there is a workhouse in Great Britain exempt from it. Neither is there one free from asthma, and yet all the world knows a royal duke suffers from it as much as a coalheaver might do;...

1842, [anonymous collaborator of Letitia Elizabeth Landon], chapter LV, in Lady Anne Granard; or, Keeping up Appearances. […], volume III, London: Henry Colburn, […], page 74