Professor Moll’s Method of determining the Amount of Sunshine on Greenhouses

Among the posthumous writings of Prof. Dr. J. W. Moll in the Groningen University Museum one rather comprehensive manuscript is to be found, dating from the year 1915, on the Groningen University Botanic Garden. This manuscript which for several reasons has never been published, contains a paragraph on the determination of the hours during which the sun, when shining, may reach by its direct beams a given greenhouse or any particular object on any day of the year.