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CHAPTER XII. 
OF THE MACHINE OF CTESIBIUS FOR RAISING 
WATER TO A CONSIDERABLE HEIGHT. 
IT is now necessary to explain the machine of Ctesibius, 
which raises water to a height. It is made of brass, and 
at the bottom are two buckets near each other, having 
pipes annexed in the shape of a fork, which meet at a 
basin in the middle. In the basin are valves nicely 
fitted to the apertures of the pipes, which, closing the 
holes, prevent the return of the liquid which has been 
forced into the basin by the pressure of the air. Above 
the basin is a cover like an inverted funnel, fitted and 
fastened to it with a rivet, that the force of the water 
may not blow it off. On this a pipe, called a trumpet, 
is fixed upright. Below the lower orifices of the pipes 
the buckets are furnished with valves over the holes 
in their bottoms. Pistons made round and smooth, 
and well oiled, are now fastened to the buckets, and 
worked from above with bars and levers, which, by their 
alternate action, frequently repeated, press the air in 
the pipes, and the water being prevented from returning 
by the closing of the valves, is forced and conducted 
into the basin through the mouths of the pipes; whence 
the force of the air, which presses it against the cover, 
drives it upwards through the pipe: thus water on a 
lower level may be raised to a reservoir, for the supply 
of fountains. Nor is this the only machine which Ctesi- 
bius has invented. There are many others, of different 
sorts, which prove that liquids, in a state of pressure