ClipArt ETC
"This was invented in 1865 by H. Sprengel. The instrument, in its original (simplest) form, consists of a vertical capillary glass tube a of about 1 mm. bore, provided with a lateral branch b near its upper end, which latter, by an india-rubber join governable by a screw-clamp, communicates with a funnel. The lower end is bent into the shape of a hook, and dips into a pneumatic trough. The vessel to be exhausted is attached to b, and, in order to extract its gas contents, a properly regulated stream of mercury is allowed to fall through the vertical tube." —The Encyclopedia Britannica, 1903

Air-Pump

"This was invented in 1865 by H. Sprengel. The instrument, in its original (simplest) form, consists…

A glass cylinder is open at the bottom, having a piece of bladder or thin indian-rubber tightly stretched over the top.

Burst Bladder

A glass cylinder is open at the bottom, having a piece of bladder or thin indian-rubber tightly stretched…

"To avoid friction and heat, the piston is not in contact with the cylinder in which it works."

Deleuil's Air-pump

"To avoid friction and heat, the piston is not in contact with the cylinder in which it works."

Two racks carry the pistons and work with the pinion. The pinion is turned by a double-handed lever, which is moved alternately in opposite directions.

Double-barrelled Air-pump

Two racks carry the pistons and work with the pinion. The pinion is turned by a double-handed lever,…

This apparatus consists of a bell-shaped vessel of glass, the base of which is pierced by a tube fitted with a stop-cock which enables us to exhaust the vessel of air.

Fountain in Vacuo

This apparatus consists of a bell-shaped vessel of glass, the base of which is pierced by a tube fitted…

A machine designed to suppress the dead space which limits the efficiency of ordinary air-pumps.

Kravogl's Air-pump

A machine designed to suppress the dead space which limits the efficiency of ordinary air-pumps.

Two hemispheres which can be exactly fitted on each other; their exact adjustment is further assisted by a projecting internal rim, with is smeared with lard.

Magdeburg Hemisphere

Two hemispheres which can be exactly fitted on each other; their exact adjustment is further assisted…

"To avoid friction and heat, the piston is not in contact with the cylinder in which it works."

Piston and Barrel of Deleuil's Air-pump

"To avoid friction and heat, the piston is not in contact with the cylinder in which it works."