The base of the second bottle whose lip was shown above right is displayed here.
The the lower left corner you can see evidence of the diagonal mold seam which at one time bisected the base.
In the neck on the right notice how just below the collar the mold seam goes complete around the neck. Both of these medicine bottles look much like their earlier counterparts.
the right side is crude and was disturbed by the action of marking the marking with Owens Ring.
Owens rapidly made improvements as eh redesigned his machine numerous times and eventually over came the problems of uniformity see here.
Beginning collectors often confuse an Owen's ring with a pontil mark and it is easy to see why this happens.
The pictures below are from two early machine made medicine bottles.
The glass is rough (not sharp) around the circumference of the Owens ring.
Notice also how unlike most pontil marks, the Owens ring covers the whole base of this bottle.
One approach to helping beginner identify their old bottles involves show them the bases of old bottles.
The picture below at the left shows an iron pontil on the base jof a historical flask circa 1865.
Slowly the corked top bottle began to disappear in favor of the screw top.