ARCHITECTURE. 
improper, as the cove represents the half of 
an arch upon every side of the room ; it will 
seem as if falling, from the want of an ap- 
parent support in the middle, unless the 
ceiling rise from a circular plan. Ceilings 
coved and flat are much employed in mo- 
dern apartments : they seem to be a kind 
of medium between the horizontal, and the 
various arched forms practised by the an- 
cients : they do not require so much height 
as the latter, but they are neither so grace- 
ful nor so grand. Vaulted ceilings are 
more expensive than plane ones, but they 
are also susceptible of a greater variety of 
embellishments. 
Chimnies. A chimney is an opening 
through a wall upwards, beginning .at one 
side of a room, and ending at the top of a 
wall : its use is to warm the room, and give 
passage to the smoke. That part of the 
opening which faces the room is the place 
where the fire is put, and consequently is 
called the fire-place: the tube or hollow 
proceeding from the fire-place upwards, for 
giving vent to smoke, is called the funnel, 
or flue : the stone or marble laid level with 
the floor immediately before the fire-place 
is called the hearth or slab ; and the one 
under the fire-place the back or inside 
hearth. The projecting parts of the walls 
on each side of the fire-place, forming also 
parts of the surface of the room, and stand- 
ing at the extremities of the hearth, are cal- 
led jambs : the head of the fire-place in the 
surface of a room, resting upon the jambs, 
is called the mantle : the mantle, and that 
part of the chimney resting upon it, forming 
a part of the side of the room, and also the 
whole side of the flue to the top, is called 
the breast; the side of the flue opposite to 
the breast is called the back; and the sides of 
the fire-place contained between the jambs 
and the back are called covings. When 
there are two or more chimnies in the same 
wall, the flues of which approach very near 
to each other, the thin division which sepa- 
rates one flue from another is either called 
a partition or a with ; that part of the open- 
ing or horizontal section opposite to the 
mantle of a fire-place is called the throat ; 
and that turret above the roof of a house, 
containing one or more flues, is called the 
shaft. 
Iu stone walls the most common dimen- 
sions of the sections of flues are from 12 to 
13 inches square, for fire-places about 3i 
feet wide in front ; and those in brick walls 
14 inches by 9 inches. The area of the sec- 
tion of the flue should always be propor- 
tioned to the area of the fire usually put in 
the fire-place, that is, nearly equal to the 
area of the horizontal section of the fire it- 
self, excepting at the throat. The throat 
should be immediately over the fire, and its 
horizontal dimension in the thickness of the 
wall should not exceed 4i, or 5 inches at 
most. The fuel grate, or stove, should be 
brought as near to the throat as conveniency 
may require. The coving should be placed 
bevelling nearer together at the back than 
at the jambs, making an exterior angle with 
the front of the jambs, and an interior angle 
with the back, of 135 degrees each. The 
back and covings forming the sides of the 
fire-place should be of white materials, such 
as white stone, or brick covered with plas- 
ter, which are most conveniently put up 
after the house is built. Most metals are 
unfavourable for this purpose. The top of 
the throat should be quite level, forming an 
abrupt plane. Some of the principles in 
the construction of chimnies are very well 
ascertained, others are not easily discovered 
till tried. The more the air that goes into 
the flue is rarefied, with the more force it 
will ascend, and the higher the flue the 
greater also will this force be ; therefore the 
fire should have as little vacancy on either 
side as possible, and the flue, when conve- 
nient, should be carried as high as possible, 
and not have too wide an aperture at the 
top. The situation of doors in a room, the 
grate being placed too low, and other things, 
often occasion smoke ; but whatever be the 
cause of it, if once discovered, the evil may 
easily be remedied. Circular flues are more 
favourable for venting than those whose sec- 
tions are rectangular. 
Vaults. A vault is an interior roof over 
an apartment, rising in a concave direction 
from the walls which support it, either 
meeting the vertex in a point or line, as 
when the section of the arch is Gothic ; or 
one continued areh from the one abutment 
to the other, as when the section is a semi- 
circle, or a segment less than a semicircle. 
The vertical sections of the intradoes of 
vaults may be formed by an infinite variety 
of curves ; but the most elegant forms are 
either circular or elliptic ; which forms of 
sections have been generally adopted by 
the ancients of remote antiquity, by our an- 
cestors throughout the middle ages, and by 
European nations at the present day. We 
shall therefore confine ourselves to those 
vaults which have their extradoes of circular 
and elliptic sections. 
A cylindrical vault is a plain vault, the 
