👉 The term "holoscope" refers to a device used for measuring atmospheric pressure. It is typically found in an aviation or scientific laboratory, where it is used by pilots and engineers to measure the pressure of the air around them. The device consists of a small tube that is connected to a pressure gauge and a small balloon attached to one end of the tube. When the pilot holds the balloon up against the ground, the gas in the tube will rise as pressure increases, causing the balloon to rise.
