- First name
- Balthasar
- Last name
- Monconys, de
- Date of Birth
- 1611
- Date of Death
- 1665
- Born in
- Lyon
- Died in
- -
The pneumatic air-pump experimentation, detailed by Oldenburg in his letter to Spinoza, was part of a series of barometric tests announced on 2 May 1663. These machine-made tests were performed from 10 June 1663 onward in the Royal Society, at Gresham College in Bishopsgate Street, the regular meeting place of the London Fellows (cf. Birch, 1756–7, vol. 1, p. 220; 254-5). The French savant, traveller and diplomat Balthasar de Monconys was also present during the experimentation. Later, on 30 June 1663, he met Christiaan Huygens who presented him with a drawing of his ‘modelle de sa machine pour le vuide’. Monconys published that sketch (Monconys, 1665–6, fig. 17, and p. 73), which appears to be identical to a sketch made by Huygens in 1661. See: Huygens, Œuvres complètes, vol. 17, p. 333.