Sorting through some old papers, I have come to a note in my own (very bad) handwriting describing a steam distribution system due to De Ritter. I think I must have copied the text down from the French and Flemish label of an exhibit in what was then a small railway museum in Brussels, which I think was located at the North station, now apparently superseded by Train World at Schaerbeek, which I have not visited. Unfortunately even where I can read my writing I don't understand all of the words. I think the text is explaining that the loco could run either with full pressure ("pleine pression" / "volle drucking") throughout the piston stroke or with cutoff at some point in the stroke ("à detente" / "met expansie"), which was achieved by the steam passing through two ("tiroirs" / a word I can't read exactly, something like "scheiven") before it reaches the cylinder. Is there a description in English on line anywhere? Or can our friend Jos tell us about it?