From the 60's but here are some analog computers that modeled real life ground water transport systems.
https://www.isws.illinois.edu/hilites/achieve/gwmodded.asp <https://www.isws.illinois.edu/hilites/achieve/gwmodded.asp> and the research that helped to create them: http://www.sws.uiuc.edu/pubdoc/RI/ISWSRI-62.pdf http://www.sws.uiuc.edu/pubdoc/RI/ISWSRI-51.pdf ________________________________ From: vcf-midatlantic <vcf-midatlantic-bounces@lists.vintagecomputerfederation.org> on behalf of Jeffrey Jonas via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> Sent: Friday, December 8, 2017 2:04 AM To: vcf-midatlantic@lists.vintagecomputerfederation.org Cc: Jeffrey Jonas Subject: [vcf-midatlantic] analog computers do real work I met a fellow who used an analog computer for factory molding (making parts with a heated mold). The heater control was not just a thermostat but calculated the acceleration of heat transfer to keep the part at the proper temperature. Definitely the job for an analog computer (till recently). I'm unsure what tech was used (tubes or transistors).