Aspirator: a Vessel of Water with a Tap at the Bottom (Sutton, 1904)

The simplest aspirator: a closed vessel of known volume, full of water, with a tap at the bottom. As the water runs out it draws gas in through the apparatus attached to it, and the volume of water run out is the volume of gas drawn through. Result: an aspirator that draws a measured volume of gas, for example 1/10 cubic foot, through an absorber at a steady rate. Source: F. Sutton, A Systematic Handbook of Volumetric Analysis (1904), pp. 581-582. Unknown: the vessel's material and the tap. Picture: p. 581 of the book.