First commercial use of a Harley-Davidson engine

What was the first commercial use of a Harley-Davidson engine? You know, powering something other than a motorcycle?
Hint. Herb Wagner wrote about it.

Sawmill? nope

Water pump?

[Pa]

Oil field work in Texas as pumps ? Pa

Geeze guys. Quit guessin. The answer can be found in Herb Wagners "At The Creation"

Bowling alley polishing machine...
Good book!
Stéph

Steph got the right answer