736 KANSAS CITY REVIEW OF SCIENCE. 
ble temperatures be maintained in these structures, but proper quantities of pure 
and fresh air suppUed continuously. It may be laid down as a fundamental 
principle that the warming and the ventilation of dwelling-places are equally 
indispensable to health, and that they are, to a great extent, inseparable in their 
relation to each other, and, ordinarily, in the appliances by which they are 
effected. 
Four modes of heating, which furnish at the same time different degrees of 
ventilation, comprise all in common use, viz.: the open fire-place, the close 
stove, the hot-air furnace, and the steam-heating apparatus. A comparison of 
these methods involves, for each, the cost of the apparatus and its durability, 
the cost of fuel and attendance, and the efficiency of the apparatus for heating 
and ventilation. 
The open fire and the stove furnish means for a constant supply of heat, 
through combustion of fuel, within the room to be heathed. The open fire gives 
off its heat to the walls and objects in a room only by radiation from the burn- 
ing fuel, all the air that passes the heated surfaces of the fire-place going directly 
up the chimney. Hence, this method is inefficient for heating, especially when 
the walls of the room in which the fire is placed are greatly exposed to outside 
cooling influences. Moreover, much more air than is necessary for combustion 
passes up the chimney, from the very nature of its construction; and as this air 
must pass through the room to the chimney, it is difficult in general to avoid 
cold currents of air. Remote corners are apt to receive little heat directly, and 
the full effect of the open fire for a dwelling, requiring as it must, a fire for each 
room, is attained only at a great expense of fuel. While the first cost of the fire- 
place may not be great, the cost of fuel, except when such open fires are mere 
adjuncts to some other system, renders this mode of heating, as houses are now 
constructed and occupied, quite out of the question for the ordinary householder. 
As regards ventilation, however, the open fire is of all systems the most admir- 
able. 
The second mode of heating, the close stove, is doubtless of all modes the 
most universally practiced at the present day. Whether the stove be a simple 
structure of cast or wrought iron, having an interior chamber for the combustion 
of fuel, with a plain wrought-iron pipe to lead away the gases of combustion, or 
whether this simple structure be incased or provided with additional chambers 
and pipes for the more extended circulation of the heated gases, and to furnish 
the greatest possible heating surface, the statistics of manufacture alone furnish 
evidence that there is some especial advantage in this mode of heating which 
commends it to popular favor. It is not difficult to account for the preference: 
the stove can be placed at little expense in any room of any building where 
there is a flue for carrying off" the smoke and the gases of combustion. The 
activity of the fire can be modified at will to suit any degree of external temper- 
ature; and as it is generally employed with the minimum amount of ventilation, 
and often with almost none at all, the economy of heat is all that can be desired. 
But in proportion as an active and sufficient ventilation is demanded, this effi- 
