HEATING BY HOT WATER. 183 
than usual, and a wide, flat flue is brought through 
this from the back of the furnace arch to the front 
again. This boiler is illustrated in Fig. 123, and 
may be employed to 
heat from about 
500ft. to 2,000ft. of 
4in. piping. When 
properly set it is 
a very powerful and 
economical boiler, 
but if the flues are 
so arranged that the 
draught passes from. 
the front end of the 
FIG. 123. 
flue in the crown directly back over the top of the 
boiler it will be found very extravagant in fuel and 
FIG. 124. 
little, if any, more power- 
ful than an _ ordinary 
saddle. Instead, it should 
be set with a deep, but 
narrow, flue on each 
side, with a mid-feather, 
extending to within about 
6in. of the bottom, in 
each, about half-way along 
the boiler, as previously 
described. 
The Climax boiler 
(Fig. 124) is another very powerful form of saddle 
boiler, and when properly set is one of the best of 
all this class for lengths of piping up to 2,000ft. 
