House and Garden 
cocks, etc., the boiler is absolutely safe and most 
simple in operation. Its efficiency depends upon its 
ability to produce steam quickly, maintain a steady 
water line and constant steam supply with minimum 
expense for fuel and attention. 
Low pressure hot water heating differs from the 
steam system, in that two lines of pip¬ 
ing are always used to connect boilers 
and radiators, thus completing a cir¬ 
cuit in which water flows when heated; 
either because of slight pressure exer¬ 
ted by a mercury seal, or simply by 
the law of gravity. The system is 
opened to the air through an expan¬ 
sion tank placed above the highest 
radiator in the system. I'he tank per¬ 
mits the expansion of water without 
danger and keeps the system full. It 
is indispensable. 
The boiler or heater is the same as 
that used for steam heating except 
that safety valve, steam gauge and 
other trimmings are dispensed with. 
Of necessity, the pipes are larger in 
a hot water system. It also requires 
more radiating surface to heat with 
hot water, because of more ma¬ 
terial and consequently more 
labor to install the same. Hot 
water costs more to install than 
does steam heat. I heir respec¬ 
tive merits may he found in the 
following features. 
Hot water throws off heat at 
low temperatures and continues 
to radiate long after the Are has 
died down. Steam radiates at 
212° and is easily held to required 
A cottage wanned by small hot water boiler and two radiators 
t be boiler has a combination Hre-pot, part of which is 
used to heat water tor domestic purposes 
pressure. Hot water is easily controlled and may 
he made to circulate at different temperatures so as 
to give desired amount of heat in the radiators; even 
temperature is thus most easily obtained. 
Steam heat is quick to respond to firing or drafts 
and can be entirely shut off at any radiator. 
. Either heating medium can be carried to remote 
rooms. Steam is usually preferred for distances, 
primarily because of cost of installation. Hot water 
is more economical of fuel because less intense fires 
are required. 
Steam and hot water are the most healthful of all 
artificial heating methods. The air is warmed by 
coming in contact with the heated radiators and is 
not devitalized. Hot water is considered the most 
agreeable and healthful. 
There are three different forms of heat radiation 
as employed to-day. Their method of installation is 
shown in the accompanying illustration: (A) the 
direct, (B) the semi-direct, and (C) the indirect. 
I he indirect is the ideal way of heating when 
radiators would be undesirable anywhere in the 
room. This method also permits a perfect control of 
fresh air as well as the supply of perfectly warmed air 
entering the room. It costs about one-third more 
than direct radiation (A). 
This type, the first mentioned, is the ordinary iron 
radiator. It can be selected to fit under windows, 
in alcoves, or fastened to the walls. Many harmo¬ 
nious eff ects are produced with the aid of enamels 
and bronze. 
The other type (B) is a combination of direct and 
indirect methods explained above. It is employed 
only in rooms where ventilation is naturally poor. 
Fresh air is drawn through a wall-box and made to 
circulate around the radiator. The supply of fresh 
air is controlled by a sliding damper. 
In estimating the cost of modern heating equip¬ 
ment, the householder would do well to consider the 
value of fuels in the different methods of heating. 
In houses with widely separated wings, the problem is to heat 
comfortably with economy 
The low pressure 
steam bo i 1 er is 
very simple and 
safe in operation 
66 
