Perosity is formation of bubbles inside a material. It happens in many industrial proceses, in many cases rendering the material useless.
The point of using a hydraulic is quite simple, people use it to measure and estimate velocity of water passing between at least 2 points. The way to calculate the velocity and therefore have a reason to have a hydraulic table is using hydraulic conductivity, perosity and hydraulic gradient. A different kind of hydraulic table is one that is used to move heavy machinery around shop floors or in workshop style buildings, commonly used because of the strength and the manoeuvrability to move these heavy objects without the use of a bigger machine to move it.
Mass: the amount of matter in an object. Volume: the amount of space that matter occupies. Density: mass per unit volume of a substance. Shape: the form or structure of matter. Texture: the feel or appearance of a substance's surface. Color: the property of matter that is determined by the wavelengths of light it reflects. State: whether matter is solid, liquid, or gas. Conductivity: the ability of matter to conduct heat or electricity. Solubility: the ability of matter to dissolve in a solvent.