sky-scraper, n.² — Green’s Dictionary of Slang

sky-scraper n.²

[the horse Skyscraper, sired by Highflyer, which won the Epsom Derby in 1789]

a tall horse.

1827		Sporting Mag. (N.S.) XX. 48: I should like to see him upon one of the crack Sky-scrapers of the day .
1885		‘’Arry on ’onesty’ in Punch 31 Jan. 60/1: Sufficient sky-scrapers to keep in the ’unt, with that ’igh-flyer ’Arry.