Cartography – from past to present

Cartography – from past to present

Found this on the Ordnance Survey blog, written by Gemma.

A fascinating read, and having worked in the offices mentioned, I can tell you that there are still reminants of these old ways lying around (maybe not the Ferranti computers!). A really nice read.

“My time at Ordnance Survey started with a training course on 25 January 1966 with me earning the princely sum of £446 per annum. After a few weeks we moved from to the training drawing sections at London Road. The building had been caught in the blitz in 1941 and was a shadow of its former self. At this point in time it still felt like a military organisation with military personnel occupying all of the top management positions.

Cartographer applying building stipple film to one of the original enamel positives. There is a surveyor’s BJ plate by her left elbow, and a ruling pen. Applying building stipple like this was eventually replaced by cutting the buildings out of a ‘cut and strip’ mask to match what had been scribed.

My cartography skills started with the ruling pen. We would draw a 7/1000 inch gauge line in black ink onto enamel. We were working on enamel coated zinc plates on which an image of the surveyor’s work had been printed in a light blue aniline die, at 1:1 250 map scale. Map symbols and text were added to the enamel and the finished article was used to make the printing plate At that point the zinc plate would be stripped of the old enamel image and re-enamelled to be used again.

The next development saw us cartographers scribing – etching into plastic. We initially did this by sharpening gramophone needles, before specific tools became available. This time we were working in the negative and the image was then printed in positive onto a glass surface with PVA. It was a very fiddly job as the map symbols were stuck onto the glass. You can imaging what it was like when working on a forest area – very time consuming, and during hot summer months the wax holding the film moved out of position very easily.

1:2 500 overhaul scribecoat using a straight edge.

The Romsey Road head office was already being built when I started training, but at that point we weren’t sure it would become our head office. At the interview I was told I could be based in Southampton or Kettering! I moved up to Crabwood House, on the Romsey Road site and we were all in ‘temporary’ buildings from the First World War until the new building was ready. We finally moved in during 1968–9. The ground floor was a hive of activity with our print floor, areas making scribe coats, enamelling, photo labs and much more. We had a restaurant and two ‘trolleys’ a day bring us drinks, snacks and cigarettes. Yes, cigarettes – we worked in offices full of paper and flammable liquids and we could smoke at our desks. It seems madness now, but it was normal at the time.

It was the 1970s when we first started to digitise our maps. Of course, we didn’t have any inkling about the digital era – at that point computers were huge boxes that printed lots of ones and zeros! Automated cartography started around 1974. We worked from digitising tables where we would press a button to record the point and then another button to mark the end of the feature. This was all recorded on tapes which were then stuck together and put through a processor.

The original Ferranti digitising system was blind, you didn’t see the results of your work until the results had been processed and a plot produced. Digitising was carried out at a larger scale (1:750 for 1:1 250 and 1:1 500 for 1:2 500) to make the result more accurate.

This is a first version digitising table, the cursor has no ‘yellow button’ to finish a feature. Note the enlarged negative that they are capturing the data from.

The introduction of Lites editing (laserscan interactive editing system) which came with a computer screen, meant that you could see the detail you were capturing as you carried it out. Names were added in separately and then the map and names were merged in the computer system.

Today, we’ve transferred all our small scale vector data into ArcGIS. We’ve also brought the production of Meridian 2 in-house. We’ve recently delivered a new way of delivering data for print as our printing has moved outside the business. We now do all the styling within Cartography and send the final PDF to our printers.

Cartography is constantly finding better ways to deliver and striving to be as efficient and accurate as we can be. There are always new projects to work on and new developments being put in place – but for me, cartography all started with the ruling pen back in 1966.”

If you’ve enjoyed reading John’s overview of cartography changes in the last 40 years, why not find out what our Cartography team is getting up to today?”

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