We have a number of pre-1990 surveys in mulu for which all the centreline data has been lost but we still have the drawn up surveys. We have regenerated centreline data by inventing survey stations and legs and working out XYZ coordinates for them (very laboriously)2, but now I am putting these surveys into Therion. At the moment I am using the XYZ base survey data and putting in stations for these on the plan. However the positions of these stations on the drawing are very aproximate (I don't actually have the original plot showing exactly where the made-up stations are - one can just just guess from the look of the survey). But this introduces errors of approx the width of the passage, which can be several meters, and is adding distortion to the drawings I am putting in. I am wondering if there is a better way - so I put the drawings in and say 'these are all we have - you work it out', rather than using ill-defined stations which were only made up by taking off this very same drawing in the first place but now they have been through numerous innacuracies and distortions. Can therion do this? And how would I work out the scaling? Can I use a scale bar or something and just copy the scale into each scrap? Wookey -- Aleph One Ltd, Bottisham, CAMBRIDGE, CB5 9BA, UK Tel +44 (0) 1223 811679 work: http://www.aleph1.co.uk/ play: http://www.chaos.org.uk/~wookey/