The collection consists of the following works: 1. Bogaevsky B. L. The Technique of Primitive Communist Society . 2. Lurie I. M. Techniques of Ancient Egypt . 3. Schultz P. N. Technique of the ancient slave-holding society . 4. Skrzhinskaya E . H. Techniques of the Western European Middle Ages . 5. Zeitlin E. A. Technique of the manufacturing period Bewerr: The collection is concise, but at the same time capacious and visually gives an overall picture of the level of technical development in each of the historical eras. You should not look for detailed descriptions of the same trebuchets in this collection - there are dozens of highly specialized works for this purpose. "Essays... " contain a large number of good illustrations, and are no doubt useful precisely as a wonderful popular science material, interesting even for an unprepared reader. The book is rare, you will not find in the newsstands . I highly recommend reading ..