Truly better out than in.

PF, your system isn't as random as it may seem.

It was an attempt (influenced by the metric French system) to rationalise weights and volumes.

An fluid ounce of water weighs one ounce.

A pint of water weighs one pound, as opposed to the Imperial where a pint is 20oz.

Where this became important was where you didn't have precision volume measing equipment, but you could accurately weigh an ounce and a pound.

Once you established the volume of water, you could mark the container, empty the water, fill it with the other liquid to be measured and have an accurate measure.

The first measure had to be water because water was the standard, and nothing else quite weighs the same, so a pound of wine or whisky would volume slightly less than the water, but oil slightly more.

Logic from another era.

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Calm, quiet, smooth, devastating