contents  of  the  condenser.  The  tank  should  be  provided  with  baffles
to  steady  the  flow  of  the  current.  If,  then,  the  contents  flowing  from
one  of  these  orifices  be  collected  separately  and  weighed,  and  the  result
multiplied  by  the  number  of  orifices,  the  total  weight  of  water  passing
away  per  unit  of  time  will  be  obtained.
If  S  =  weight  of  condensed  steam,  and  W  =  weight  of  injection
water,  then  total  water  weighed  =  W  +  S  per  minute.  .  .  .  (1)

If  /j  and  t2  =  initial  and  final  temperature  of  the  injection  water
obtained  by  delicate  thermometers,  then  W(£2  —  ^)  =  heat  carried
away  by  injection  water.  Let  t2  also  equal  temperature  of  feed.
Heat  supplied  by  steam  =  S(H  —  h2),  where  H  is  total  heat  of  the
steam,  and  \  =  (temperature  of  feed  —  32).  Then —

S(H  —  A2)  =  (work  done  in  heat-units  per  minute) +W(£2  —  ^)  .     (2)

Or,  if  temperature  t3  of  feed  is  not  the  same  as  that  of  the  condensed
steam,  then —

S(H  -  *,)  =  work  done  -f  S(*2  - «,)  +  W(*2  -  t,)    .     .     (3)

We  have  now  two  equations — (2  or  3)  as  above,  and  (1)  equal  to  the
numerical  value  in  pounds  of  W  +  S  by  weight  during  the  test.
By  combining  these  equations  the  value  of  S,  or  the  weight  of
steam  per  minute,  can  be  obtained.
