For near mythological geek cred you should use a Babylonian water level :) https://en.wikipedia.org/wiki/Water_level_%28device%29 https://en.wikipedia.org/wiki

For near mythological geek cred you should use a Babylonian water level :) https://en.wikipedia.org/wiki/Water_level_%28device%29 https://en.wikipedia.org/wiki/Water_level_%28device%29