Charles Darwin was the first to put wheels on an office chair in the 1840s. Darwin had his microscope sitting on a window sill where the natural light was brightest and found himself constantly moving back and forth to some barnacle specimens at his desk. In order to move more quickly between the two, Darwin removed the legs from his armchair and replaced them with the wheeled legs from his bed. This allowed him to roll quickly between desk and window without having to get up. The design of the office chair has evolved to become more stable and ergonomic through the years but the presence of caster wheels has remained a standard feature on office chairs for over 150 years now.