Green’s Dictionary of Slang

the prison treadwheel.

1859, 1860		Hotten Dict. of Modern Sl. etc.
1864, 1867, 1870		Hotten Sl. Dict.
1866		Letters by an Odd Boy 165: Some of the slang expressions, also, are simply funny; as, for example, when you call [...] the treadmill ‘a vertical case grinder,’ or a four-wheeled cab ‘a bird-cage!
1883		N. Devon Jrnl 8 Feb. 7/2: [from The Echo] The treadmill again, is more politely called the everlasting staircase, or the wheel of life, or the vertical care-grinder .

(N.Z.) drinking while standing at the bar, esp. in a crowd.

1955		B.J. Cameron Collection (TS July) n.p.: vertical drinking (n) Drinking standing up.
1959		C. Bollinger Grogs Own Country 97: First target [i.e. of the campaign against six o’clock closing] was the ‘vertical swill’ type bar.
1966		G.W. Turner Eng. Lang. in Aus. and N.Z. 131: This [i.e. six o’clock closing] gives in New Zealand the terms vertical drinking (in crowded bars with standing room only) [DNZE].
1988		McGill Dict. of Kiwi Sl. 119/2: vertical drinking standing room only drinking in some pubs in the good old, bad old days.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

the vagina.

1971		R. Condon [title] The Vertical Smile.
1998		Digital Underground ‘The Odd Couple’ 🎵 My nose be in her booty / My tongue be in her vertical smile.
2003		at SublimeDirectory.com 🌐 ‘The most comprehensive vagina nickname list in the world!’ [...] bearded clam, vertical smile, beaver, cunt, trim, hair pie.