This is an excellent book about masonry heaters. I highly recommend it. It also tracks the use of fire by man in an interesting chronology. It covers Russian, European, and Scandanavian masonry heaters, as well as the hybrid type German and Austrian Tile stoves, going all the way back to the Roman hypocaust ( http://www.answers.com/topic/hypocaust ), one of the first attempts at taming wood heat using thermal mass (stone and water). http://www.amazon.com/Book-Masonry-Stoves-Rediscovering-Warming/dp/1890132098 I checked a copy out from my local library and enjoyed every page. Marty, Thanks for the info. One question for you: From ignition, how long before you feel some heat? For the DIY'er. I've read several articles of people contructing these beasts. One potential problem is cracking of the inner core. Even the pro's have them crack, especially on the first ones they build. A store-bought inner core would reduce that sequelae.