Message #49341

[forestman]

I can say that there doesn't seem to be any relation between degree of hollowing and opening size.

The second smallest opening of 3.4 mm is on the bottle hollowed out to almost egg shell thinness which is an anomaly and the smallest opening of 3 mm is on what is one of the better hollowed coral bottles.

It does suggest that there was a degree of uniformity in sizes of drill bits/core drills that were made.

I assume there would be some degree of polishing of the openings to remove any marks left by the drill bits and slight tolerances in making drill bits to exact sizes.

When you look at the four most common openings and include openings of 0.1 and 0.2mm larger you account for 42% of the bottles. If you then include 0.1 and 0.2 mm smaller you account for 60% of the bottles.

Regards, Adrian.