48 
BULLETIN 1136, U. S. DEPARTMENT OF AGRICULTURE. 
more, trouble may result if the steamed stock is not carefully cooled 
in saturated air to the drying temperature before the curtain is rolled 
up and drying resumed. 
VENTILATED COMPARTMENT KILNS. 
Ventilated compartment kilns also vary considerably in detailed 
design. Most of them, however, are arranged for cross circulation, 
Fig. 7.— Cross section of ventilated compartment kiln. 
and the fresh air is usually brought in at the bottom and distributed 
throughout the length of the kiln by means of ducts under the lum- 
ber. Ventilating flues are usually provided along the length of the 
kiln on both sides, and outlets to these made at various heights and 
in various manners, in accordance with the ideas of the individual 
manufacturer. The entire possible range of locations for these out- 
lets is represented in commercial practice, at least one manufacturer 
