There are beautiful melonshaped chandeliers on both sides
of the Main Concourse and several more in Vanderbilt Hall.
They were always thought to have been bronze but they had been
covered with dirt for many years. The chandeliers were taken down
and cleaned. Remarkably, with just one cleaning the glistening gold
was revealed. Note the bare light bulbs. In 1913 electricity was new
and not widely used by normal households, so the New York Central Railroad
wanted to give the sense of grandeur, luxury, and opulence to its train terminal,
and did this by showing off the nickel and gold- plated chandeliers with electric light bulbs.

from: grandcentralterminal