Good morning all I have just put together a Therion Extended Elevations <https://therion.speleo.sk/wiki/extend> page, having convinced myself that I have almost figured out how to make them work. You can navigate there from the wiki start page <https://therion.speleo.sk/wiki/start> , via the 'Data Organisation' link. Thanks and apologies to Marco Corvi, for the inspiration and words I have borrowed from his page. Marco, is it OK? It is not quite complete yet (I have a history of not completing projects) however if someone can direct me to the centreline and drawing data for the famous Therion Extended Elevation Control <https://therion.speleo.sk/samples.doc/25.html> sample, then I might remain inspired enough to generate a more comprehensive set of examples. Enjoy your caves Bruce