"High Five" in Railway Conductor book from 1894 

Mistakenly removed a reference to this 1894 bit of text in my recent clean-up, the source is available on Google Books, "The Conductor and brakeman, Volume 12 By Order of Railway Conductors and Brakemen" it is on page 225, and the text reads: "Progressive high five was the order of the evening and refreshments were served [...]". It's surely not a reference to the hand gesture, but any ideas what it could be? Deserves some discussion. I read the whole page, no clear idea of what it could be, but it sounds abstract, like some kind of bonhomie or pleasant ambiance rather than a tangible object or act.