Notes on the letter of Johannes Marcus Marci to Athanasius Kircher (1641)
This letter merely mentions Barschius and is included for completeness. The ‘magnetism book’ is Kircher’s Magnes, published in 1641.
Ages at this time of the individuals involved
Rudolph II: dead for 28 years
Jacobus Horcziczky: dead for 17 years
Raphael Mnihovsky: 60
Georgius Barschius: about 55
Johannes Marcus Marci: 45
Athanasius Kircher: 38