Tobacco curing system

Claim 1

IN A TOBACCO CURING SYSTEM A KILN IN WHICH TOBACCO MAY BE HUNG FOR CURING, AN OPENING ADJACENT THE LOWER EDGE OF A WALL OF THE KILN, A SECOND OPENING ADJACENT THE UPPER EDGE OF SAID WALL, A DUCT EXENDING BETWEEN THE TWO OPENINGS, AND AIR-CONDITIONING MECHANISM ASSOCIATED WITH THE DUCT AND LOCATED AT THE LOWER END THEREOF, AND COMPRISING A WALL EXTENDING ACROSS THE DUCT AND HAVING A CENTRAL CIRCULAR OPENING THEREIN, A SUPPORT MEMBER EXTENDING DIAMETRICALLY ACROSS THE SAID OPENING AND BELOW IT, BEARINGS CARRIED BY SAID SUPPORT MEMER, A SHAFT JOURNALLED IN SAID BEARINGS, AND CARRYING A FAN CAPABLE OF SWEEPING SUBSTANTIALLY THE ENTIRE OPENING, MEANS TO RIVE SAID FAN, A SECONDARY DUCT EXTENDING FROM THE EXTERIOR OF THE PRIMARY DUCT ACROSS THE BOTTOM OF THE PRIMARY DUCT AND BENDING UPWARDLY TO TERMINATE BELOW SAID FAN, A FUEL BURNER IN SAID SECONDARY DUCT, MEANS TO ADMIT COMBUSTION AIR TO THEINTERIOR OF SAID SECONDARY DUCT, MEANS RESPONSIVE TO THE TEMPERATURE WITHIN THE KILN TO CONTROL THE FUEL BURNER, MEANS TO ADMIT EXTERNAL AIR TO THE DUCT, DAMPER MEANS TO EXHAUST AIR FROM THE DUCT AND MEANS RESPONSIVE TO THE WET-BULB TEMPERATURE OF THE AIR WITHIN HE KILN TO CONTROL THE DAMPER MEANS.