182 GREENHOUSE CONSTRUCTION AND HEATING. 
boiler, as shown in the illustration. Horizontal mid-feathers 
are also sometimes used. 
A form of saddle boiler with waterway end or back is 
sometimes adopted, an 
opening being left in 
the upper part of the 
back to allowthe flames, 
etc., to pass into the 
flues. This form is 
illustrated in Fig. 121. 
FI. 121. Another and really 
excellent type of saddle 
boiler is provided with a waterway end, with two oval 
Openings in the sides, at the far end, and about half-way up 
the boiler, leading into the flues. These are usually made 
in cast-iron only. I had one under my care at one time 
that did really splendid work, heating several hundred feet 
of 4in. piping—a heavy load in proportion to its size— 
quite easily and well, 
with a small consump- 
tion of fuel and very 
little care. This boiler, 
which is known as 
Jones’ patent, is illus- 
trated in Fig. 122. 
The next type of iat cio 
saddle boiler to be 
considered is the ‘‘ terminal-end and flued,”’ which is also’ 
known as the Chatsworth boiler. This is similar in form 
to an ordinary saddle, though usually made somewhat flatter 
at the top and sides, but the crown is considerably deeper 
