KEEPING WARM 
realized that a stone or brick chimney 
A'as not only safer but also absorbed 
neat from the fire and later radiated it 
oack into the room. To take advantage 
af this form of heat storage, people 
began to build ever more massive ma- 
sonry chimneys. In homes in northern 
Europe, these chimneys evolved into a 
huge central structure that might incor- 
porate a number of fireplaces, ovens, and 
flues, with a sleeping loft on top where a 
bed could be kept deliciously warm. 
As firewood became scarce, however, 
people looked for a heating system that 
would be more efficient than an open 
fire. At the end of the eighteenth cen- 
tury, the American-born physicist 
Count Rumford endeavored to make a 
science of fireplace efficiency, designing 
a fireplace that radiated a much greater 
percentage of its heat into the room. 
Benjamin Franklin had an even better 
idea, putting the fire in a metal box 
installed within the fireplace. His design 
included a separate air box through 
which fresh air could be circulated and 
heated, uncontaminated by the gases of 
combustion. Later manufacturers sim- 
plified the concept, moving the stove out 
into the middle of the room, where its 
heat could radiate in all directions. The 
Franklin stove was the “Model T” of the 
heating business, mass produced and 
the pride of households all over the 
I country. 
With the Franklin stove came the 
revolutionary idea that a fire could heat 
a house indirectly — by heating the air, 
which could then be circulated to keep 
people warm anywhere in the house. 
This idea initiated the changeover from 
; a radiant to a convective system of heat- 
| ing. Improvements were made to ex- 
l tract more and more heat from the 
i firebox, and the stove was transformed 
into a furnace. For the first time a 
i building was seen as an enclosure for a 
bubble of warmed air, and attention 
began to be paid to making the enclo- 
sure more airtight. Merely blocking out 
the rain and wind was not sufficient in 
an air-heated house, for if a building still 
leaked air, pressure from the wind could 
drive all of the heated air to one side of 
the house and out through the walls. 
In the nineteenth century, the new 
scientific understanding of the processes 
of convection and radiation brought a 
flurry of efforts to design the perfect 
furnace — safe, clean, efficient, and in- 
expensive. At first, natural convection, 
which depends on gravity, was most 
commonly used to move warmed air 
PMOUCTO» 
ueurs 
Chivas Brothers make the world s finest Scotch. 
And the same renowned Chivas quality and tradition goes into its 
equally-regal Lochan Ora Liqueur. With a unique taste all its 
own. Lochan Ora is to he lingered over— sipped slowly, savored fully 
Its expensive but. then, good taste invariably is. 
Lochan Ora. 
The Imported Liqueur from Chivas Brothers. 
70 HHOO» • l#*ORT£D BY GENERAL WWt & SPIRITS CO N Y N Y 
