CHIMNEYS. 15 
nence is farther from the wind than the chimney com- 
manded. ‘To explain this a figure may be neceffary. 
Suppofe thena building whofe fide A, happens to be expof- 
ed to the wind, and forms a kind of dam againtt its 
progrefs. The air obftructed by this dam will like Fl, 
water prefs and fearch for paflages through it; and 
finding the top of the chimney B, below the top of the 
dam, it will force itfelf down that funnel, in order to get 
through by fome door or window open on the other fide 
of the building. And if there be a fire in fuch chimney, 
its {moke is of courfe beat down, and fills the room. 
Remedy. \ know of but one, which is to raife fuch 
funnel higher than the roof, fupporting it, if neceflary, by 
iron bars. For a turn-cap in this cafe has no effect, the 
dammed up air prefling down through it in whatever po 
fition the wind may have placed its opening. 
I know a city in which many houfes are rendered fmoky 
by this operation. For their kitchens being built behind, 
and connected by a paflage with the houfes, and the tops 
of the kitchen chimneys lower than the top of the houfes, 
the whole fide of a itreet when the wind blows againft its 
back, forms fuch a dam as above defcribed; and the wind 
fo obftructed forces down thofe kitchen chimneys, (efpe- 
cially when they have but weak fires in them) to pafs 
through the paflage and houfe, into the ftreet. Kitchen 
chimneys fo formed and fituated, have another inconve- 
nience. In fummer, if you open your upper room wind- 
dows for air, a light breeze blowing over your kitchen 
chimney towards the houfe, though not ftrong enough to 
force down its fmoke as aforefaid, is fufficient to waft it 
into your windows, and fill the rooms with it; which, be- 
fides the difagreeablenefs, damages your furniture. 
7. Chimneys, otherwife drawing well, are fometimes 
made to fmoke by the improper and inconvenient fituation 
of a door. When the door and chimney are on the fame 
fide of the room as in the figure, if the door A, being in 
the 
