Na podlagi treh listin iz arhiva Postojnske jame je razvidno, da so priprave na načrtovani obisk cesarja Franca Jožefa 1856, vključevale uporabo barvnih luči in drugih posebnih načinov razsvetljave kot tudi steklenih napisov za označevanje dvoran in kapnikov. Obisk je bil odpovedan v zadnjem trenutku, vendar je prišel cesar v jamo 15 tednov kasneje in zelo verjetno je, da so omenjeno razsvetljavo uporabili ob tej priliki. Three documents in the archives of Postojnska jama show that the arrangements for the planned visit of Emperor Franz Joseph to the cave in 1856 included the use of coloured lights and other special illumination as well as glass transparencies for labelling halls and speleothems. Although this visit was cancelled at the last minute, the Emperor did come to the cave 15 weeks later and it is shown that almost certainly the illumination was used then.