532 New Patents 
horfes on the land is to be avoided. The 
Patentee alfo calculates on a great faving 
both in feed and in the labour of hortes 
(of which laft he afferts that one in four is 
- faved); and the harrow may alfo be ufedas 
a rake, or for any'other fmilar purpofe. 
—2 Lo 
DR. ANDERSON for @ HOT-HOUSE. 
We extra& from the Monthly Agri- 
cultural Mifcellany of the ingenious writer 
who is the inventor of this improved hot- 
houfe, the following account of its con- 
ftiruction :— 
The Patentee firft points out the defects 
in the prefent conftructién of thefe houfes, 
owing to which the heat of the fun is not 
turned to all the advantage of which it is 
capable. In the houfes now in ufe, ‘the 
soof-glafles of hot-houfes are almof uni- 
verfally laid into the frames, by lapping 
one pane over the other leaving an open 
{pace between, each pane, through which 
the air may freely pafs and repais, whi lit 
the panes in front are clofely puttied all 
round. It is this communication with the 
open air at the upper part of the houfe, 
that is its chief defect, for, as the effect 
of heat upon any quantity of air (and in- 
deed on fluids in general) is to make the 
mafs of air thus heated to rife in a body 
to the upper part of the vefiel in which 
the air is contained; fo it is in a hot- 
houfe. As foon as the fun’s rays pene- 
trate through the glaffles, the air within 
the houfe becomes heated, and, rifing to 
the top of the houfe, it paffes out into the 
epen air, and continues to do fo for feve- 
ral hours before the lower part of the houfe 
is fenfibly warmed. Thus the effect of 
the-morning fun is loft for fome hours, 
and in the evening, when the warm air 
within the houfe begins to cocl, and to 
econtraét in bulk, the cold air from with- 
out finds its way through the top glaffes, 
and cools the troufe in the moft, expeditious 
manner poffible. ‘Io remedy thefe incon- 
Yeniences Dr. Anderfon propofes the fol- 
lowing conftruction for houfes to force 
vines, or fuch as require a fimilar tempe- 
rature. ‘The houfe is to be made of the 
ufnal dimenfions, but with a glafs roof 
entirely flat; and, as it never requires to 
be opened,- all the feams and junctures 
muft be clofely pafted up. Over this flat 
roof another floping roof is to be thrown, 
which laft alfo is better made of glafs, but 
may be built of flate. A chamber, in the 
form of a common garret, is thus made 
above the hot-houfe, which is to ferve as 
@ referveis for the heated aix, The upper 
‘ 
lately enroiled, 
chamber has communication with the open 
air only at its iower part, that is, juft 
over thereof of the lower houfe. It com- 
municates with the lower houfe by a pipes 
which pafles through the glais roof et this 
houic, and. is prolonged nealy to the 
ground below, and to the top of tic vpper 
chamber above. By this conftruciion, as 
foon as the morning-fua begins © oma 
the air of the lower nouic, if ries ae 
roof, and, not finding aay opcniig there, 
it accumulates in that oart, whili che 
cool air is forced througa the pipe inte 
the upper chamber. Thus the ftracum of 
warmer air is conftantly increafing cown- 
wards from the rgof till the whole of the 
lower honfe is warmed. After this the 
air afcends warm through the communi- 
cating pipe into the upper chamber, or 
refervoir for heated air; and here too, as 
below, it afcends to the top of the cieling, 
forcing out the cooler air contained in the. 
upper chamber, which pafles away thro” 
the openings which. are left above the 
floor of this chamber, or the roof of the 
lower room. 
During the whole of this heating pro-. 
cefs, the vines which are trained all along 
under the glafs roof of the lower chamber 
are immerlfed in warm air on every fide. 
In the evening, when the fun is off, the 
warm air contraéts by cooling, and the 
outer air rufhes in through the only com- 
munication which the houte has without ; 
that is, through the openings juft over 
the glals-roof into the upper chamber. 
As this outer cold air is heavier than any 
part of the air within either chamber, it 
[July I ; 
- 
4 
can only gradually enter in proportion as - 
the inner air recedes, and the current ~ 
through the chambers is exaétly reverfed, 
whilit the lower chamber recéives all the 
fiore of heated air from the refervoir be- 
fore the cooler air can reach it, and the 
roof of the Jower room on which the vines 
are trained, muft be the laft place in the - 
whole building that can be cooled. 
The Patentee is fully of opinion, that 
in moderately fine weather the warmth of 
a few hours of fun would be felt in the 
part on which the grapes are trained, at 
leaft till the return of the next-day7s-fun, 
and thus a permanent heat might be kept 
up without any artificial heat whatever 
from fuel, fufficient to ripen grapes al- 
ways with certainty, and much earlier 
than in the open air. 
Dr. Anderfon likewife fuggefts, that 
the upper houfe might ferve as a hot- 
houfe of inferior rank, and particularly 
well for a green-houfe or confirvatory. 
I We 
