Excise duty on processed textile fabrics using hot air stenter fixed per installed chamber, tied to factory average value of fabric. Fixes an excise duty regime for processed textile fabrics made exclusively with a hot-air stenter by independent textile processors, levying duty on a per-chamber-per-stenter-per-month basis according to the factory's average value of processed fabric; prescribes methods to count chambers (including pro rata rules and treatment of attached equipment), sets reference dates for existing and new factories, requires declared averages for new or closed units with year-end reworking, mandates prior approval for changes affecting chamber count, and apportions aggregate duty equally between two statutory duties.