Yesterday was a bit more encouraging. I dug a Wyeth & Bro. Phila. with what I believe is a tooled lip. It looks as if it's pretty common, clear glass. Thd strangest thing happened, though. It had a small (maybe 1" long) crack near the shoulder on obverse last night while cleaning it. Tonight when I went to photo it, the crack had expanded, easily 3x's as long as last night. Could this have been due to the hot water I used to clean it?
Rapid temperature change can definitely crack glass items even when no preexisting defect is visually evident. My own thought is that bottles, due to stresses inherent in their various contours and material thicknesses, especially prevalent in older blown examples, are more susceptible to thermal shock than other glass products such as window glass. That said, I suspect any experienced structural firefighter can relate anecdotes of heated windows shattering upon being sprayed with cold water.