Description
Where extremely high temperatures were needed, such as when smelting ore, it was common to blow air into the bottom of the fire with a bellows. One type of bellows consisted of two vertical cylinders covered with thick leather. The operator stood on these, pulling the leather up with an attached strap and then pressing it down with his foot to create the rush of air, which was channeled into the furnace.
Translation
Not all present-day English speakers are familiar with the structure or operation of a bellows, so several common-language English translations have avoided using the word in JER 6:29 by rendering the first line of this verse as “The fire is fanned to make it hotter” (NCV), “The furnace burns fiercely” (GNT), or “in a fiery furnace” (CEV).