I have... hinted at the probability that Boyle himself was involved only in a very limited way in 'his' experimental manipulations. The device which became known as the machina Boyleana [air pump] was almost certainly constructed for him by remunerated assistants Ralph Greatorex and Robert Hooke, and even the extent of Boyle's rule in its evolving design remains unclear. The glass J-shaped tube that yielded his law of pressures and volumes was again almost certainly made for him and had to be manipulated by him in collaboration with assistants, if not solely by them. The furnaces in his laboratory, and the alembics in which long-term distillations were performed, were probably tended by assistants.