Perfume leaks at hourly intervals onto the copper face of this clock by German designer Patrick Palcic, which was presented at this year's IMM Cologne.
Palcic created the clock, named Es Liegt was in Der Luft – or There Is Something in the Air – to offer an alternative way to tell the time.
"The olfactory clock allows the user to experience the passage of time in a different way," Palcic told Dezeen. "Instead of the time being read, as with other timepieces, it hangs in the air and is inhaled."
Instead of hands, 12 small holes are punctured around the perimeter. Each hour is assigned a different fragrance, which is in the mechanism behind the clock face.
The copper dish turns slowly, so that its perforations hit 12 o'clock at hourly intervals, triggering a drop of essence to be released.
The perfume trickles down the copper face, which is heated up to cause the scent to evaporate. It also it oxidises the metal, leaving lighter markings on the surface.
"From the uppermost hole, at 12 o'clock, the first liquid flows over the copper plate and leaves a trace on the surface," the designer explained. "The shell heats up and the first essence floats in the air."
"The expiration repeats itself an hour later, only the plate is advanced by a hole," he continued. "The process starts from the beginning."
Es Liegt was in Der Luft is one of a number of atypical clocks. Among them is Breaded Escalope's touch-responsive clock that tells the time with shadows, while Zelf Koelman's Ferrolic clock uses magnetic ferrofluid to tell the time.
IMM Cologne takes place from 16 to 22 January 2017. Products launching at the fair include a collection of tables designed by architect Hans Bølling, a hybrid bed-desk frame by Pieter Peulen that helps students make the most of tiny living spaces and stools by Fabio Hendry and Martijn Rigters featuring patterns made from burnt hair.