Green’s Dictionary of Slang

spellken n.

a theatre.

c.1785		‘The Dog and Duck Rig’ in Holloway & Black I (1975) 80: For fear that some gallows old scout / If you at the spell ken can hustle, / Shou’d fix you in working a clout.
1823		(ref. to late 18C) Byron note to Don Juan Canto XI 149: The following is a stanza of a song which was very popular, at least in my early days [...] ‘If you at the spellken can’t hustle / You’ll be hobbled in making a clout’.
1832		Egan Bk of Sports 14: If you at the spell ken can’t hustle / You’ll be hobbled in making a clout.
1860		Hotten Dict. of Modern Sl. etc. (2nd edn) 223: SPELLKEN, or speelken, a playhouse.
1873		Sl. Dict.
1881		Newcastle Courant 2 Sept. 6/5: Passing — spellken, I saw a crowd waiting for admission, and Downy Sam in the middle of it, buzzing for clocks.
1895		Crowe Aus. Sl. Dict. 79: Spelken, a theatre.