This is a really odd and specific question, and I'm not sure this is even where to ask. A few weeks ago I thought about making a clock based on water flowing from an orifice. The obvious issue is that the flow rate would vary significantly based on environmental conditions around the clock. Does anyone know of a liquid or maybe a powder that will flow more consistently from a container into another across normal temperature and pressure shifts?
The obvious first guess would be sand like in an hourglass, but I was hoping someone knew of a better solution because the flow rate of sand is finicky in other more unpredictable ways.
I should add that the supply container will always be topped off with more media so that the mass (pressure) of liquid or powder is not changing with time.
