Profusely illustrated with BW photos and illustrations. Contents include all types of underground lighting: ancient and medieval mine lighting, beginnings of manufactured lighting, hanging oil, candle, oil wick, flame safety, acetylene carbide, flame surveyor's, and crossbreed lamps. If you want to know anything about Mine Lighting this book is a complete text. Henry died a couple of years ago so the book will become even more collectable. DJ is worn