A—PROJECTING MOUTH OF CONDUIT. B—PLANKS FIXED TO THE MOUTH OF THE
CONDUIT
WHICH DOES NOT PROJECT.
feet high and three feet in diameter, bound with wooden hoops; it has a
square blow-hole always open, which catches the breezes and guides them
down either by a pipe into a conduit or by many pipes into the shaft. To
the top of the upper pipe is attached a circular table as thick as
the bottom of the barrel, but of a little less diameter, so that the barrel may be
turned around on it; the pipe projects out of the table and is fixed in a
round opening in the centre of the bottom of the barrel. To the end of the
pipe a perpendicular axle is fixed which runs through the centre of the barrel
into a hole in the cover, in which it is fastened, in the same way as at the
bottom. Around this fixed axle and the table on the pipe, the movable
barrel is easily turned by a zephyr, or much more by a wind, which govern
the wing on it. This wing is made of thin boards and fixed to the upper
part of the barrel on the side furthest away from the blow-hole; this, as I
have said, is square and always open. The wind, from whatever quarter of
WHICH DOES NOT PROJECT.
feet high and three feet in diameter, bound with wooden hoops; it has a
square blow-hole always open, which catches the breezes and guides them
down either by a pipe into a conduit or by many pipes into the shaft. To
the top of the upper pipe is attached a circular table as thick as
the bottom of the barrel, but of a little less diameter, so that the barrel may be
turned around on it; the pipe projects out of the table and is fixed in a
round opening in the centre of the bottom of the barrel. To the end of the
pipe a perpendicular axle is fixed which runs through the centre of the barrel
into a hole in the cover, in which it is fastened, in the same way as at the
bottom. Around this fixed axle and the table on the pipe, the movable
barrel is easily turned by a zephyr, or much more by a wind, which govern
the wing on it. This wing is made of thin boards and fixed to the upper
part of the barrel on the side furthest away from the blow-hole; this, as I
have said, is square and always open. The wind, from whatever quarter of
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