GLASS-MAKING. 



163 



projecting neck of the bottle the glass is still plastic hands it 

 over to the gatherer, and with a fresh blowpipe repeats his labor. 

 Such constant blowing largely develops the muscles of the cheek, 

 but the exercise is not unwholesome. It is impossible by methods 

 like these to obtain bottles of uniform thickness, yet the varia- 

 tions are much less than one would suppose. 



Fig. 4. Putting the Bottle in the Mold preparatory to the Final Blowing. 



In contact with the iron of the mold the bottle cools very rapid- 

 ly. Almost as soon as the blower takes away his pipe, the mold 

 may be opened and the bottle removed. The little fellow who 

 does this is called a " snapper." He seizes the bottle with his iron 

 forceps and transfers it from the mold to a pair of scales near by. 

 A small square of asbestus cloth remains permanently on the scale- 

 pan, as contact with the cold iron would be apt to crack the glass. 

 All bottles, except the very small ones, are thus weighed, and any 

 that show either a deficiency or an excess in weight are rejected. 

 There will always be a slight variation, but it must be within 

 narrow limits, not exceeding, for instance, an ounce in bottles in- 

 tended to weigh seventeen ounces. Comparatively few bottles are 



