Standing near the amazing Grote Electriseermachine in Teylers Museum where Einstein, Napoleon and the Tsar were standing too, is a real previlege. On the bureau of Lorentz was the same sort of inktcushion I use (19th century, Mûr de Bretagne). After explaining my 15 and 17 year old grandchildren what sort of cushion it was, I promised them to write and draw with east-indian ink (my daily joy).