NOTICE  OF  M.  CAERE'S  APPARATUS  FOR  MAKING  ICE.  103 
by  the  patentee,  who  also  claims  the  application  of  the  power  of 
absorption  due  to  mutual  affinity  as  a  means  of  producing  vacuo, 
volatilization,  the  removal  of  heat,  and  the  consequent  produc- 
tion of  cold.    This  machine  is  called  "  Jack  Frost,  Jr." 
Althougli  the  apparatus  is  complex,  it  does  its  work  well,  and 
makes  three  tons  of  ice  per  day  when  in  constant  operation. 
Without  an  outline  engraving  it  will  be  impossible  to  convey  to 
the  reader  a  correct  idea  of  its  details,  involving  as  they  do  much 
tubing ;  yet  we  will  endeavor  to  describe  its  principal  features. 
It  may  be  premised  that  the  form  of  ammonia  used  is  the  con- 
centrated aqua  ammonia,  containing  26  per  cent,  of  gaseous 
ammonia,  and  that  there  is  a  constant  pressure  in  the  apparatus 
when  in  full  operation  of  about  200  pounds  to  the  square  inch, 
or  thirteen  atmospheres. 
The  apparatus  consists  (1)  of  a  cylindrical,  dome-topped,  verti- 
cal boiler^  about  9  feet  high  and  2J  in  diameter,  into  which  250 
gallons  of  the  ammonia  are  introduced,  part  of  which  enters  the 
exchanger,  the  complement  and  the  absorption  vase,  to  be  des- 
cribed.  A  large  tube  issuing  from  the  dome  connects  it  with  (2) 
the  liquefaetor^  which  is  an  extensive  series  of  connected,  nearly 
horizontal  tubes,  contained  in  a  sheet-iron  tank  filled  with  cold 
running  water.  In  this  the  gas,  under  the  great  pressure  and  the 
cold,  is  liquefied,  its  latent  heat  being  carried  olf  by  the  cold 
water,  whilst  the  liquid  ammonia  passes  out  at  the  lowest  end  by 
a  small  tube  into  (3)  the  recipient,  where  it  collects.  This  vessel 
is  connected  by  a  tube  with  (4)  the  distributing  valve,  which  dis- 
tributes it,  by  means  of  six  small  tubes  of  l-16th  of  an  inch 
calibre,  into  six  stacks  of  zig-zag  tubes,  contained  in  the  freezing 
cistern.  The  freezing  cistern  consists  of  a  wooden  tank  lined 
with  iron,  about  five  feet  long,  three  wide,  and  three  deep,  in 
which  are  placed  six  lines  of  vertical  zig-zag  tubes  above  noticed, 
into  which  the  liquefied  ammoniacal  gas  enters  from  the  dis- 
tributing valve.  Between  these,  forty-eight  copper  cans  or  freez- 
ers, .filled  with  water,  are  placed,  and  the  whole  interior  of  the 
tank  is  filled  with  a  bath  of  strong  brine,  or,  preferably,  solution 
of  chloride  of  calcium,  which  is  incapable  of  being  frozen  by 
the  temperature  produced,  and  is  made  to  circulate  between  the 
tubes  and  freezing  cans  as  a  carrier  of  heat,  by  a  stirring 
