Barograph used in gliding competitions to record elevation changes.
https://diqn32j8nouaz.cloudfront.net...r_fullsize.jpg
https://diqn32j8nouaz.cloudfront.net...1_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...234#post184809
https://www.homemadetools.net/forum/...449#post212025
https://www.homemadetools.net/forum/...424#post204763
https://www.homemadetools.net/forum/...404#post154620
