In Jon's own words "the book is a culmination of over 15 years exploration underground and archival research" It's a credit to Jon's expertise and determination it's full of his own colour photographs, with black and white historical record photographs. He has also provided a lot of detail of the industry itself with the workshops and machinery supported by diagrams and drawings , there are also plans of the mine . Plus a nice touch an aerial photograph with a labelled photo on opposite page thus not detracting from the original
https://www.moorebooks.co.uk/aberllefeni-slate-quarry-a-history-of-the-last-underground-slate-working-in-wales.html
