What is black glass?

Today, black glass is formed when 63% silica sand 22% soda 15% limestone are heated together and stirred until the mixture is melted to a smooth paste. A...

What is stroke formula?

A = pi * B^2 / 4. The volume swept out during any complete stroke is the piston area times the stroke: V = pi * S * B^2 / 4. This volume is called the wo...