However, many specialty bottles, most notably liquor decanters, had the pontil scars ground away leaving a shallow depression where the scar used to be (Munsey 1970). Pontil rods were (and may still be) used up until recent times at Mexican decorative glass factories and by small scale art glass producers in the U. Fire polishing was reported to have been developed by the English in 1834, though some American flasks from an earlier period appear to have been fire polished.
Pontil scars on all types of "utilitarian bottles" (discussed below) became ever increasingly unusual as the 1860s progressed and largely disappeared by the late 1860s or early 1870s as various "snap" or snap case tools dominated the task of grasping the hot bottle for finishing (click on the previous link to view the discussion on the main Bottle Bases page).
However, the transition time for conversion from the pontil rod to the snap case was lengthy for utilitarian bottles.
The rod had to be long enough so that the heat transference from the extremely hot (2000 F.) bottle did not reach the hands of the pontil rod holder.
A pontil rod held the bottle during the steps in the bottle blowing process where the blowpipe is removed (cracked-off) from the bottle and that break-off point is "finished", i.e. (Click empontilling and cracking off to see an illustration of these processes.) The process of applying the pontil rod to the base of a glass item (or the later use of a snap tool) and the detachment of the blowpipe was called "reversing" by glass makers (Trowbridge 1870).
There were also regional glass maker differences for this transition period also.