- W A L 
nii! ft obferve, that when the two ovens are joined to- 
gether, there fhould be a partition Wall at lead three 
bricks thick between them, otherwife the fires will 
foon deftroy it •, and if there fhould be the leaft hole 
in the Wall, through which the fmoke of the two fires 
can communicate, it will prevent their drawing. 
The lower flue, through which the fmoke firft paffes 
from the fire, may be two feet and a half deep : there- 
fore the back Wall fhould be at leaft two bricks and a 
half thick, as high as to the top of this flue ; and then 
it may be fet off to two bricks, which muff be conti- 
nued to the top of the Walk The fecond flue, which 
fhould return over the firff, may be made two feet, the 
third a foot and a half, and the fourth one foot deep *, 
which four flues, with their coverings, will rife near 
eicrht feet in height ; fo that there will be about two 
feet left for fixing of the frames at the top to fupport 
the glaffes, and for the coping of the Wall. And thefe 
four returns will be fufficient to warm the air in the 
frames, for the fmoke will have loft its heat by the 
time it has paffed thus far. 
In the carrying up of thefe Walls, there fhould be fome 
ftrong iron hooks fattened at convenient diftances, 
which fhould project about two inches from the Wall, 
to which the trellis muft be fattened which is to fup- 
port the trees. Thefe hooks fhould be long enough 
to fatten into the back Wall, for the Wall in front 
being but four inches thick, will not be ftrong enough 
to fupport the trellis •, but in placing of them care 
fhould be taken not to lay them crofs the middle of 
the flues, becaufe they would obftrud the clearing 
the flues of foot whenever there fhould be occafion ; 
fo that the beft way is to lay them juft under the tiles 
which cover each flue, at about three or four feet afun- 
der, which will be near enough, provided the hooks are 
made fufficiently ftrong. As the flues muft be well 
pargetered with loam on their infide, fo likewife fhould 
the loam be fpread under the tiles which cover them, 
to the thicknefs of the hooks, that the flues may be 
very fmooth, otherwife the foot will hang to the iron 
hooks, and flop the fmoke from patting. It will be 
very proper to cover thefe flues on the fide next the 
trellis with Hop-bags, or fome fuch coarfe cloth, in 
the manner as hath been direded for the ftoves, 
which will make them fo tight that no fmoke will find 
its way into the frame, which, without this covering, 
it is very apt to do through the joints of Walls, efpeci- 
ally when they are fo thin as thefe muft be built ; and 
this covering will alfo ftrengthen the wall of the flues, 
and join the whole work together. If at each end of 
thefe flues there are jfmall arches turned in the back 
Walls, in fuch a manner that there may be holes open- 
ed to clean the flues of foot whenever there is a necef- 
fity for it, the trouble will be much lefs than to open 
the flues in front, by which there will be no damage done 
to the trees, nor will the flues be in the leaft injured 
by this, which they muft be, when they are opened 
in front. 
The borders in front of thefe hot Walls fhould be 
about four feet wide, which will make a fufficient de- 
clivity' for the Hoping glaffes •, and in thefe borders 
there may be a row of Dwarf Peas planted to come 
early, or a row of dwarf Kidney-beans, either of 
which will fucceed very well ; and if they are not 
planted too near the trees, will not do them much 
injury. On the outfide of thefe borders fhould be low 
Wa)ls eredted, which fhould rife four or fix inches above 
the level of the borders, upon which the plate of tim- 
ber fhould be laid, on which the Hoping glaffes are to 
reft ; and this Wall will keep up the earth of the bor- 
der, and alfo preferve the wood from rotting. 
The glaffes which are defigned to cover thefe Walls, 
muft'be divided into two ranges, for as they ’muft 
reach from the ground-plate (juft above the level of 
the border) to almoft the top of the Wall, they will 
be more than twelve feet long, which will be too 
great a length for Angle frames, which, when they 
are much more than fix feet long, are too heavy to 
move, efpecially if the frames are made of a proper 
ftrength to fuftain the glafs. Thefe frames fhould 
W A L 
be contrived in fuch a manner, as that the upper row 
may Aide down •, and by making on one fide three 
fmail holes in the wood- work which fupports the 
frames, at about a foot diftance, and having a fmail 
iron pin to fix into them, the top glaffes may be let 
down one, two, or three feet, according as there may- 
be occafion to admit air. The lower row of glaffes 
may be contrived fo as to take eafily out ; but as they 
muft lie doping, and the upper row muft bear on 
them, they cannot be contrived to Aide upwards ; nor 
indeed will there be any occafion for their moving, 
becaufe it is much better to let the air in at the top. 
than in the front of the trees. 
The floping timbers which are to fupport the glafs 
frames, muft be fattened at bottom into the ground- 
plate in the front of the border, and at the top into 
ftrong iron cramps fixed in the upper part of the Wall 
for that purpofe. Thefe timbers fhould be made of 
Fir, which will not twift, as Oak and fome 1 other wood 
will, where it is laid in fuch pofition. They muft be 
made fubftantial, otherwife they will not laft many 
years, efpeciallly as they are defigned to be movea- 
ble. On the top of thefe fhould be fixed a ftrong 
board, under which the upper row of glaffes fhould 
Aide. The ufe of this board is, to fecure the upper 
part of the glaffes from being raifed by the winds, 
and alfo to keep the wet from getting to the trees j 
therefore it fhould be joined as cloie as poffible to 
the Wall, and fhould projefl about two inches over 
the glafs frames, which will be enough to throw the 
wet on the glaffes, and likewife to fecure them fail 
down. 
The breadth of thefe frames for the glaffes may be 
about three feet or a little more, according as the di- 
vifions of the length of the Wall will admit ; for a 
fmail matter in their width is of no conlequence, 
provided they are not too wide to be eafily moved j 
for when they are wider than a man can eafily reach 
his arms to manage, they will be very troublefome to 
carry from one place to another. The bars of thefe 
frames, which are to fupport the glafs, fhould be 
placed lengthwife of the frames *, for when they are 
placed acrols, they flop the moifture which is lodged 
on the infide of the glaffes, and caufe it to fall in drops 
on the borders at every bar, which will be very inju- 
rious to any plants which are put there ; and if it falls 
on the trees will greatly damage them, efpecially when 
they are in bloflom. The lead into which the glaffes 
of thefe frames are fixed, fhould be very broad, and 
the joints well cemented, otherwife the wet will find 
an eafy paffage through, and do great damage to the 
fruit. 
At each end of the range of glaffes, there will be 
an angular fpace between the glaffes and the Wall, 
which muft be clofely flopped to prevent the air from 
getting in, which might greatly injure the fruit. Thefe 
are by fome perfons clofely boarded up ; but if they 
are clofed with glaffes, fo contrived as to open to let in 
air at proper times, it will be of great advantage ; be- 
caufe when the wind may be ftrong againft the front- 
glaffes, one or both of thefe end-glaffes may be open- 
ed, according to the warmth of the air inclofed, 
which will be often very ufeful to cool the air, and to 
admit a fmail quantity of frefh air to the fruit. 
The forts of fruit which are ufually planted for 
forcing, are Cherries, Plums, Peaches, Apricots, 
and Neflarines, but the laft-mentioned rarely fuc- 
ceed well, nor will the trees continue long, fo that 
they are fcarce worth planting againft hot Walls. As 
for the Vines, I would propofethey fhould be planted 
by themfelves againft a particular Wall ; for as they 
will require more air to be admitted to them when 
they begin, to ffioot, than any of the above-mentioned 
fruits, they will not all fucceed if they are included 
in the fame frame. As to the others, they will do 
very well in the fame borderland will demand the 
fame temperature of warmth. The beft of thefe forts 
to plant againft thefe hot Walls, arexhofe here men- 
tioned : 
Cherries. 
