Noah’s ark, n. — Green’s Dictionary of Slang

Noah’s ark n.

[coined by Punch, the term supposedly reflected the similarity of the coat to those worn by Noah and his children in toy Noah’s arks]

a long, closely buttoned overcoat, fashionable at the time.

1860		Hotten Dict. of Modern Sl. etc. (2nd edn).
1864, 1867, 1870		Hotten Sl. Dict.