272 
THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, February 5, 1861. 
any reasonable distance from it, a pipe may rise to any lieight 
and dip again, provided there is an air-pipe at tbe highest point; 
but the rise and dip should not under such circumstances be 
repeated. It is sometimes desirable, as in passing some doorway, 
to lower the pipes even below the boiler j but when this is the 
case, the pipes must first rise rather more above than it is 
desirable to sink them below that level, and it should not be 
repeated—in fact, it is best to avoid ever having a pipe lower 
than the boiler! I have met somewhere an example like fig. 2Z. 
A, The boiler ; B, an open cistern ; c, D, points where air-pipes 
should be fixed, and we would even wish one to be at E. Rut 
for some great necessity the dotted lines will show a far more 
satisfactory mode of heating, the lines dotted showing various 
point# where the pipes might be placed. 
there would require to be five holes iu each cistern instead of 
three ; or, better still, have additional T-pieces for the flow and 
return pipes, and give each pit its cistern for itself. By this 
cistern mode, from the pressure given, the heated water will 
circulate freely on any level, provided it be above the boiler. 
Even then, when many holes for pipes are in a cistern, some will 
’take more than their share at times ; but, when once known, 
that is easily guarded against, by regulating the opening by the 
plug. I like oak or deal plugs for this purpose as well as any. 
Some friends may say, Why have these cisterns at all, when 
by means of a main flow and return carried across tbe ends of 
these pits, we could, by means of a valve, turn-on top or bottom 
heat at wijl ? We have no objection whatever, only many of 
these valves must be so far under the ground level, and bad to 
Fig. 23. 
The great advantage of hot water is the ease with which a 
number of houses may be heated from one boiler. Fie/. 24, shows 
the sections of three ranges of pits—say each 50 feet long, so 
supplied with top and bottom heat, each with an open cistern 
raised to regulate that top or bottom heat at will. The dotted 
line a, is the ground level. The flow-pipe 5 communicates 
directly with each cistern. There are two more holes besides 
containing the mouth of pipes, to be open, shut, or regulated at 
pleasure, by plugs. 6 is the flow-pipe for bottom heat, joining 
pipe 3, which goes along to the farther end, rising two or three 
inches, having an air-pipe there, and returning in pipe 4, which 
is joined to the main return 4. 7 is the flow-pipe for top heat 
at front 1, which also going to the further end, and being 
supplied with an air-pipe there, comes back as 2, which is again 
joined to the maimreturn 4. 
get at when out of repair. With the open-cistern mode it is 
hardly possible for anything to go wrong. Mr. Weeks heats 
his huge parallelogram of houses in the mode you propose. A 
flow and return pipe goes through the houses on a low level, 
below the pathway as far as I recollect, and by merely having 
connecting-pipes with these fitted with valves, he can give what 
heat he likes to a house, and top and bottom heat at will, and 
may arrange his pipes any way he likes, provided there is an air- 
pipe at the highest point, and none are below the main flow' and 
return. Our friend, Mr. Eraser, at Luton Hoo, has lately had a 
large range of houses heated by one boiler, the main flow' and 
return pipes going under the back pathway, which is covered 
with stout slate. With these mains, the pipes at ends and 
fronts of the different houses are connected by a pipe with a 
valve in it, so that any house in the range may be heated at will 
Fig. 24 . 
By such a plan there is some extra piping wanted to go 
to and return from the cistern; but the plugs are all under 
control, and as simple plugs will do as well as the finest 
brass valves, the expense of the latter is avoided. It will 
easily be seen that by continuing the flow and return, five 
pits may be heated instead of three, if the boiler is powerful 
enough ; or, supposing that these three pits ran eastward, other 
three might run westward with a pathway between them, only 
and to the temperature desired. The range previously, I think, 
had three or four boilers. The change was made by Mr, 
Ormson, and Mr. Fraser speaks highly of the saving in labour 
and fuel. 
A very beautiful range of span-roofed houses standing north and 
south might be so heated ; the houses separated from each other 
for 20 feet or so, and all connected with a glass-covered verandah 
on the north side, with the main flow and return pipes under 
