Now three chimneys built.
In response to community concern that the company's three smokestacks were offensive due to their resemblance to the joss sticks used in the rituals of ancestor worship and funerals, Hongkong Electric built a fourth stack. Because the additional smokestack was not necessary at that point in time, it went unused, leading to the popular notion that the chimney was a "dummy."
Source: http://www.fundinguniverse.com/company-histories/hongkong-electric-holdings-ltd-history/