When you're hiring a tree surgeon, according to the March 23'29 New Yorker, you don't want to hire some lazy guy from the gutter...you want a man who can do this:
They're members of the Davey Institute of Tree Surgery "Tumbling Team," of course! Because the Davey Institute knows that tree surgeons must have "physical energy," and I guess they might want to go into Vaudeville if the tree thing doesn't work out.
It amazes me that there ever WERE tree surgeons, and I'm almost as amazed to discover that they still exist. I assumed from watching cartoons that the tree surgeons rushed around and pressed stethoscopes against the trunks of sick trees, but apparently their job is more sedate than all that, despite the existence of the Davey Institute Tumbling Team. I think they basically go around and write reports.
The massive two-page advertisement in this New Yorker, however, makes me think that tree surgeons back then would work for either rich landowners or for people who ran orchards. The advertisement doesn't describe what the tree surgeons actually DID -- referring to their actions as simply "the work" -- but it must have been a huge business, considering this was the Davey Institute class of 1929:
That's a lot of tree surgeons.