Green’s Dictionary of Slang

(drugs) an opium pipe.

1938		D. Maurer ‘Lang. of the Und. Narcotic Addict’ Pt 2 in Lang. Und. (1981) 103/1: gongola. An opium pipe.
1949		Monteleone Criminal Sl. (rev. edn).
1953		Anslinger & Tompkins Traffic In Narcotics 309: gongola. An opium pipe.
1961		W. Randle ‘Payola’ in AS XXXVI:2 109: Maurer and Vogel add gongola.