Since 1903 Neubronner had been using pigeons to exchange prescriptions and urgent medications with a sanatorium a few miles from his home in Kronberg near Frankfurt. A pigeon lost during one of these flights had delighted Neubronner by returning to its dovecote four weeks later, safe and sound. The episode gave Neubronner the idea of creating lightweight, wearable cameras to record his couriers’ flights. He built several models which included a pneumatic timing mechanism to activate the shutter at set intervals, leather harness, and aluminium breastplate. Neubronner would take the pigeons up to 60 miles away before releasing them, knowing that they would want to take the most direct route home to unburden themselves. To increase the mobility of his fleet, he also built a horse-drawn dovecote with an attached darkroom.