When  the  cylinder  is  full  of  water  this  float  is  at  the  upper
part  of  the  cylinder;  when  steam  is  admitted  into  the  top
of  the  cylinder  it  presses  the  float  down  and  expels  the  water
at  a  high  mean  velocity.    After  a  certain  portion  of  the  stroke
has  been  made  the  admission  of  steam  is  shut  off  automatically,
and  the  rest  of  the  stroke  is  performed  by  the  expansion  of
the  steam,  the  velocity  of   ejection    decreasing    as  the  float
approaches  the  bottom   of  the  cylinder.      The  exhaust  valve
to  the  condenser  is  then  opened,  and  as  the  steam  rushes  out
from  above  the  float  a  vacuum  is  formed,  and  the  water  enters
the  cylinder  partly  through  the  ejecting  nozzle  and   partly
from  a  separate  valve  communicating  with  the  water-space  of
the  surface  condenser.     The  float  is  thus  raised  again  to  the
top  of  the  cylinder,  after  which  the  operations  described  are
repeated.    In  the  Hydromotor  there  are  two  cylinders  working
alternately :  Dr.  Fleischer  proposes  in  larger  or  swifter  vessels  to


*  For  particulars  seo  the  two  pam-      Fleischer.    Kiel  1881.    See  abio  £a-
phlets  entitled  Ler  Hydromot&r  and     yineering  of  September  9, 1881.
Die  Physik  des  Eydromoiora    by  Dr.
