Alexander Leopold Zellner was a composer and organist. He had a strong interest in organ building and gave several lectures on the subject. This book contains ten of his lectures, which, according to the author, are not intended to help someone build an organ or organ pipe themselves. However, they enable the organist, whose organ has suffered damage or deficiencies, to recognize these issues and possibly repair them on their own. In his lectures, Zellner also describes the functioning of an organ, its components, and the system of the blower. This work from 1893 remains an informative and interesting read for anyone interested in historical organs.