45, CORNHILL, B.C., AND 122, REGENT STREET, W., LONDON. 



479 



FIG. 2927. 



FIG. 9240. 



FIG. 2934. 



3 10 



5 10 

 2 10 



2927 Model of Centrifugal Pump, for raising water by means of Centrifugal 



force, combined with atmospheric pressure (fig. 2927) . 5 10 



Appold's Pump has been most advantageously applied to drainage purposes, 



very large quantities of water being rapidly and easily raised by it to small heights. 



It has been found particularly useful for draining marshy or fen land. 



This pump was worked on a grand scale at the Exhibition of 1851. 

 Model of Barker's Mill: by this machine a rotatory 

 motion is obtained by the centrifugal force of the 

 water employed ........ 



Model of Archimedes' Screw, or Water Snail, a 

 machine for raising water to small heights requiring 

 little power, with glass tube or worm . 

 Model of Hero's Fountain, invented 120 years B.C. 

 Mongolfier's Water Earn : this machine, by the momen- 

 tum acquired from the flow of water through a pipe, 

 forces a small column to a considerable height* . 

 Apparatus for illustrating the laws by which fluids 

 Spout through various adjutages . . . . 3 



Apparatus for showing that more water flows from a 

 short tube than through a simple aperture of equal 



diameter 



Apparatus for exhibiting and illustrating the Centre of 

 Buoyancy and Meta-Centre as applied in ship-building 



(fig. 2934) 



A Series of Six Glass Tubes, of varying internal 

 diameter, for showing capillary attraction (fig. 2935) 

 Two Plates of Glass, arranged for showing the hyper- 

 bolic curve produced by capillary attraction (fig. 2936) 

 2937 Hollow Glass Balloons and Figures, or Cartesian Divers, 

 for ascending and descending in a tall air-tight vessel 

 of water, as the pressure on the surface is increased 



or diminished . . 



Ditto In Glass vessel complete (fig. 2938) . 



Glass Model of Diving Bell, with Syringe (fig. 2939) . 



2928 



2929 



2930 

 2931 



2932 



2933 



2934 



2935 



2936 



880 



30 550 



110 



136 1 10 



10 6 



15 6 



2938 

 2939 



2 

 12 

 3 10 



* Now need on alarge scale for raiting Water to small heights where water is abundant. 



