Or you could ues the 5 gallon method
Option 1: Drain tanks, close drain
Fill five gallon pail, empty into gravety fill
Count the number of times you do this, Multiply by five, measure water remaining in pail when tank is full, and subtract.
Option 2; Fill dank
Drain into five gallon pail, count number of times you empty pail, multiply by five and measure amount in the final drain, add.
Example, 11 fills, 8 gallons remaining (Method one) 52 gallons
-0r- Emptied it 10 times, 2 gallons left, 52 gallons (method 2)
That' show tank capacities have been measured since some achient dude ran through the streets stark naked shouting EUREKA, EURAKA (Which means I've found it) What had he found that was so exciting.....
A way to keep his head firmly mounted on his shoulders where it belonged.
Because he'd been told a head would indeed roll (As in fact it did) his or, the thief's.. Depending on if he could prove the theft. He did, so he lived.
Home is where I park it!