I just received my copy of the book that the BHI published of the proceedings of the memorial seminar for Derek Pratt. If your interested in watchmaking at the highest level you should get a copy of this book. Derek was a watchmaker at the level of a George Daniels but not as well known. His specialty was remontoires he made a series of tourbillion pocket watches in the 1980's and 1990's that had remontoires on the escapements and was working on a remontoire wrist watch at the time of his death as well as making another Harrison H4. While I can't write a proper review I hope what I have written here makes you aware what a fine book this is and a good read.