I always have wondered about this building/numbers in Union Square… here is what I have found on the internet…

“Metronome is an investigation into the nature of time. The work references the multiple measures of time that simultaneously inform and confound our consciousness of the moment within the continuum. This composite work intends to evoke contemplation on the dynamic flux of the city. The elements suggest the instant and infinity, astronomical sequence, geological epoch and ephemerality. Metronome is meant to be integral to the very history, architectural fabric, spirit and vitality of the city. Ultimately, the work is an ode to mortality and the impossibility of knowing time.”

http://metronome.related.com/statement.htm

[Kristin Jones / Andrew Ginzel], October 1999