design was the catalyst for much later improvement and innovation. The first rotary fan used in Europe was for mine ventilation during the 16th century, as illustrated by Georg Agricola (1494-1555).

John Theophilus Desaguliers, a British engineer, demonstrated the successful use of a fan system to draw out stagnant air from coal mines in 1727--ventilation was essential in coal mines to prevent asphyxiation--and soon afterward he installed a similar