Ventilator, model of patent by Robert Boyle, mahogany frame, British, mid 19th century

Made by Robert Boyle & Son Ltd, an engineering company specialising in ventilation, this model was made for hygiene exhibitions to demonstrate how their ‘Air Pump Ventilator’ worked. If air is blown through the model the balls of cotton wool (which represent the stagnant air in a building) will rise, showing how it is immediately drawn out of the room.

Disease was thought to be caused by bad air and smells from human waste, rotten rubbish and stagnant water, so good ventilation was considered to be important. Robert Boyle saw himself as a public health campaigner and wrote many ‘Sanitary Crusades’ on the topic of public hygiene.