Topic: Crackled Glass Insulator

[antiquerose123]

Crackled Glass Insulator.  This is marked with a D in a diamond (dominion glass) then a dash (-42).  I am from Canada.  I thought I read that this may mean the year, as in 1942.  Is this correct?

I have been told (?) that these are *misfired* when made.  You can not feel any of the cracks on the inner, or outer surface...it is all smooth.  The cracks are truly inside.  Are this a misfired Insulator Glass?

Any comments/corrections about the age/maker/style/ and history and/or knowledge about crackled glass Insulators.

Thanking you in advance...

antiquerose123 (rose)