BUILDING. 
tai, the eoiirsing joints will be planes tend- 
ing to the axis, and the transverse joints 
will be either vertical circular rings, or 
conic surfaces, having the same conunou 
axis with the intrados. 
Stone WuUs. Stone walls are those built 
of stone, with or without cement in the 
joints ; the bedding joints have most com- 
monly a horizontal position in the face of 
the work ; and this ought always to be the 
case whe n the top of a wall terminates in a 
horizontal plane or line. In bridge build- 
ing, and in tiie masonry of fence walls 
upon inclined surfaces, the bedding joints 
on the face sometimes follow the direction 
of the top or terminating surface. 
'I'he footings of stone walls ought to be 
constiucted of large stones, which if not 
naturally near tlie square from the quarry, 
should be reduced by hammer dressing to 
that form, and to an equal thickness in the 
same course ; for, if the beds of the stones 
of the foundation are suffered to taper, the 
superstructure will be apt to give way, by- 
resting upon mere angles or points ; or upon 
inclined surfaces the footings ought to be 
well bedded upon each other with mortar, 
and all the upright joints of an upper loot- 
ing should break joint ; that is, they should 
fall upon tiie solid of the stones below, and 
not upon the joint. 
The following are methods practised in 
laying the footings of a stone foundation : 
when the walls are thin and stones can be 
got conveniently, that their length may 
reach across each footing from one side of 
the wall to the other, the setting of each 
course with whole stones in the thickness of 
the wall should be pseforred. But when 
the walls are thicker, and bond stones in 
part can only be conveniently procured, 
then every other succeeding stone in the 
course may be a whole stone in the thick- 
ness of the wall ; and every other interval 
may consist of two stones iii the breadth of 
the footing ; this is placing the header and 
stretcher alternately, like Flemish bond in 
nine-inch brick woik. But when bond 
stones cannot be had convenientiy, every 
alternate stone should be in length two- 
thirds of the breadth of the footing upon 
the same side of the wall ; then upon the 
other side of the wall a stone of one-third of 
the bi eadth of the footing should be placed, 
opposite to one of two-thirds ; and one 
of two-thirds opposite to one of one-third ; 
so that the stones may be placed in the 
same manner as those of tlie other side. 
In broad foundations where stones cannot 
be procured for a leiigtli equal to two- thirds 
of the foundation, then build them alter- 
nately, with the joints on the upper bed tf 
each footing, so that the joint of every two 
stones may tall as nearly as possible in the 
middle of the length of the one, or eaclihid- 
joining stone ; observing to dispose the 
stones alike on each side of every footing. 
A wall, the superstructiRiC of which is built 
of unhewn stone laid in mortar, is called a 
ruble wall. They are of tvto kinds, coursed 
and uncoursed. The most common kind of 
ruble is the unconrsed, of which tlie greater 
part of the stones is ci ude, as tliey came out 
of the quarry, and tlie rest hammer dressed. 
This kind of walling is very inconvenient 
for the building of bond timbers ; but if 
they are to be prefen-ed to plugging the 
backing must be levelled in every height in 
which the bond timbers are disposed. The 
best kind of ruble is the coursed ; the courses 
are all of accidental thicknesses, adjusted by 
a sizing rule, as the slating of a roof ; the 
stones are either hammer dressed or axed. 
This kind of work is favourable for tiie dis- 
position of bond timbers, but as all build- 
ings, constructed either in whole or in part 
of timber, are liable to be burnt, strong well 
built walls should never be bound with tim- 
ber, but should rather be plugged, for if 
such accident take place tlie walls will be 
less liable to warp. 
Walls faced with squared stones, hewn or 
rubbed, and backed with ruble stone or 
brick, are called ashler. The medium size 
of each ashler measures horizontally in the 
face of the wall about 28 or 30 inches; in 
the altitude one foot, and in tlie thickness 
8 or 9 inches. The best figures of stones 
for an ashler facing are formed like trun- 
cated wedges ; that is to say, they are thin- 
ner at one end than at the other in the 
thickness of the wall, so that when the stones 
of one course, or a part of a course, are 
shaped in tiiis manner, and alike situated to 
each other, the back of the course will form 
an indention like the teeth of a joiner’s saw, 
but more shallow in proportion to the lengtli 
of a tootli ; the next course has its indenta- 
tions formed the same way, and the stones 
so selected, that the upright joints break 
upon the solid of the stones below. 
By these means, the facing and backing 
are toothed together, and unquestionably 
stronger than if the back of each aslf ;r 
had been parallel to the front surface of the 
wall ; as the stones are mostly raised in 
quarries of various thicknesses, in an ashler 
facing, it would greatly contribute to the 
strength of the work to select the stones in 
each course, so tliat every alternate ashler 
