The original 1907 Times Square New Year's Eve ball was covered with iron and wood.
The first ball was built for the celebration introducing 1908 at One Times Square. It was about five feet in diameter and weighed roughly 700 pounds. Its surface carried 100 light bulbs, making it a bright visual signal for the crowd below and for newspaper readers who would learn about the event afterward.
The design changed repeatedly over the following decades. Later balls used aluminum, crystal, and increasingly sophisticated lighting systems, so modern photographs can make the original construction easy to misremember. The current ball is far larger and uses Waterford crystal panels and LED lighting.
The ball itself was part of a publicity strategy by The New York Times. The newspaper had moved into the tower in 1904 and used public celebrations to promote both its new headquarters and the renamed Times Square. That origin explains why the object began as a temporary attraction rather than an ancient custom.