Ingeniøren Thorkild Schiøler gennemgår i denne rigt illustrerede bog romerske og islamiske vandhjul. Schiøler afgrænser i indledningen bogens emne således:
”The subject of this book is water-lifting machines built of wood, clay, stone and rope, in which one wheel, or more, forms a principal component of the structure. Despite the narrowness of the field, the subject is both vast and complex, and other limitations have proven to be necessary. For example, the type of wheel to which “The great Wheels of Ḥamā” belong is only touched upon in brief.”
