1. Artisanal knowledge and experimental natural philosophers
2. Brachner , Alto . 1986. “'Die Münchener Optik in der Geschichte. Entstehung, Unternehmungen, Sternwarten, Lokalitäten, Ausbreitung'”. 282ffMunich on the considerable advances made with spectroscopes between 1860 and 1861, and, thesis, about the cooperation between scientists and the Steinheil company