The Book of Lumenus unlocks the fascinating world of light and lighting. The book is written primarily for the layman with a basic interest in physics and public lighting. This means that the various subjects are presented in a descriptive way, that is, without graphs, equations and the like.The contents of the Book of Lumenus are not just limited to the typical lighting issues. The book also includes the observation process and is provided with anecdotes from the practical experience of the author himself to clarify the implications of everyday practice. Furthermore, on a number of subjects the book offers an explanation with respect to content. This makes the Book of Lumenus also interesting for lighting experts.