In manufacturing the glass bulb, a type of "ribbon machine" is used. A continuous ribbon of glass is passed along a conveyor belt, heated in a furnace, and then blown by <answer>precisely aligned air nozzles</answer> through holes in the conveyor belt into molds. Thus the glass bulbs are created. After the bulbs are blown, and cooled, they are cut off the ribbon machine; a typical machine of this sort produces 50,000 bulbs per hour. The filament and its supports are assembled on a glass stem, which is fused to the bulb. The air is pumped out of the bulb, and the evacuation tube in the stem press is sealed by a flame. The bulb is then inserted into the lamp base, and the whole assembly tested.
What blows the glass bulbs into their characteristic shape?
precisely aligned air nozzles