Regular readers of this blog know that I enjoy collecting 19th century trade cards. You can read all about my advertising collection here.
Mechanicals are relatively rare because they weren't preserved in albums like other trade cards. They almost always were also distributed with expensive purchases, like reapers.
The mechanicals are literally windows onto American farm life of the 1880s, and the latest technology of that time.
The reverse of the Hayes mechanical reads:
SEE OUR PLANTER EXHIBIT
SECTION E. COLUMN R-7.