Topic: help Info old drinking glass

[Paul S.]

sincere thanks to Steven and Peter  -  I realized afterwards that this old chestnut had come up before, and I'd foregotten completely what the correct answer was.
How errors get proliferated!!            Have a look in 'The Arthur Negus Guide to British Glass' by John Brooks.........page 33, bottom picture No. 15, for which the caption reads......... "the typical 'Y' (or 'T') mark was left by the gadget, which was used as an alternative to the pontil iron during the C19"  (my contents and italics in brackets).
And I'm sue I've seen the same mis-information elsewhere.

So, it's caused by when shearing the foot away from the pontil iron  -  and proabably true to say found on pieces of lesser quality.

[flying free]

found on pieces of lesser quality? why?  would that be because those of better quality would have had a polished pontil mark which would have polished out these shear marks?
m

[Lustrousstone]

It's not shearing off the pontil iron; glass is cracked off because it's near enough solid at the pontil iron, which is why you have a broken bit to polish away, or not. It's the shearing of the molten glass to drop a gob the size you want into the mould or just to detach it from a bigger bit.

If your sheared-off gob is then transferred to a pontil iron, the shear mark would disappear. You get a mark because the shears are cooler than the glass, so the area of glass touched cools slightly.

[flying free]

so it doesn't indicate lesser quality, it's just a function of the process of how the piece was made?
m

[johnphilip]

Over the years i have heard both gadget mark or shear mark  i wonder if Adam can put it to rest , i will also ask a friend who s job was footmaker at Whitefriars . jp
Also the mythical scorpion mark on the bottom of some Murano clowns it that a shear mark or a gadjet mark ?