Examples of these two types of pumps are shown at the right. The lifting pump at the top has a valve in the piston and one at the bottom of the cylinder. On the upstroke, the piston valve is closed, and water is sucked from the reservoir past the open lower valve. The lower valve closes on the downstroke, and the water in the system is forced through the piston valve and out the spigot. In theory the reservoir could be as much as 34 ft below the surface of the water in the pump cylinder, but the inevitable leaks, plus the presence of some air already in the cylinder at the bottom of the stroke, reduces this value to 26 or 28 ft.     The basic forcing pump at the right below is designed to push water from the output pipe. There is only one valve, which opens on the upstroke to fill the cylinder with water, which is then forced out of the delivery tube on the downstroke. Early hand-pumped fire engines, where the object is to produce a stream of water, rather than raising water to a height above the pump, used pairs of forcing pumps arranged so that one cylinder is moving up while its mate is moving down.

More sophisticated forcing pumps have a second valve on the output side which kept the water already in the discharge tube from rushing back into the cylinder. These glass pump models These pumps, at Denison University, are listed in the 1881 Queen catalogue at $2.00 each.     The piston packing is soft string, wrapped around grooves in the glass pistons.

The lift-pump model at the left is in the Millington/Barnard Collection at the University of Mississippi.    It was likely purchased in the second half of the 1850s by Prof. Frederick A.P. Barnard, the second Professor of Natural Philosophy, 1854-1861.

This model of a lift pump is described in the 1928 catalogue of Max Kohl of Chemnitz, Germany. It is 38 cm high, and is in the apparatus collection of Case Western Reserve University in Cleveland, Ohio.

   Some manufacturers produced combination demonstration lifting and forcing pumps. The two examples below are in the collection of historical instruments at Transylvania University in Lexington, Kentucky. They were bought from Chevalier of Paris at a cost of 345 francs (about $70) each.

   The pump at the left below is from Benedictine College in Atchison, Kansas, and at the right is a pump in the Smithsonian Institution collection. They are both unmarked

This model pump is in the Garland Collection of Classical Physics Apparatus at Vanderbilt University. The quote below is from the catalogue to the collection that was written by Prof. Robert T. Lagemann in 1983:    "Standing some 43 cm high, this model water pump bears the name (in two places) of C. SCHOTT, who was the University's instrument maker from 1875 to 1894. It is surmised that he repaired it at one time and added parts of his own fabrication, while a fairly complicated casting and other parts are the work of the original artisan.

   The Model Fire Pump by Lerebours et Secretan of Paris below is in the Garland Collection at Vanderbilt University. It consists of two pump cylinders that are actuated alternately as the handles are moved up and down. The cut at the left, from the 1875 English edition of Ganot's Physics, shows that the two cylinders feed water to the pressure chamber in the middle of the pump. When the water level in this chamber rises above the exit orifice Z, the water is ejected through hoses onto the fire. The pressure chamber, coupled with the fact that there are two cylinders, helps to ensure a steady stream of water.

The Lerebours et Secretan fire pump model at the left is in the Millington/Barnard Collection at the University Museum at the University of Mississippi.     It was certainly bought by Prof. F.A.P Barnard of Mississippi in the second half of the 1850s. It was expensive, costing 350 francs (about $70) and had to be shipped from Paris to Oxford by way of the Mississippi River and then overland to Oxford.