Conheim's Clock, by Rudy de Harak

Graphic designer Rudolph de Harak designed the unusual digital clock visible on the Water Street side facade of 135 John Street in 1971. The 50-foot-tall clock was commissioned by owners of the building next door, 200 Water Street. It consists of 72 illuminated squares with the numbers 1 through 12 on the top row and numbers 00 through 59 in a grid below. The clock is designed to tell time by illuminating the hour at the top of the grid, with the minutes and seconds flashing in the squares below.