Here is Samuel Rogers in 1855 who is concerned about some fashionable pronunciations that he finds offensive, and he says "as if contemplate were not bad enough, balcony makes me sick." (Laughter) The word is borrowed in from Italian and it was pronounced bal-COE-nee.
Este es Samuel Rogers en 1855, preocupado por formas de pronunciación que estaban en boga y que le parecían ofensivas, y decía: "como si contemplate no fuera lo suficientemente terrible, balcony me enferma". (Risas) La palabra viene del italiano y se pronuncia bal-CÓ-ni.