Society of Glass Technology · [Sheffield] · leaf 167
NOLOGY. the outside of the block is a line which might at first sight be mis-taken for a crack. The part where the piece has been masoned wasmarked in tlie same way. The cut was made and the sectionpolished to show how far this mark penetrated. The lines are due to a dry mould and the way filling… … Fig. 10. intervals to the top of the piece. The marks may be avoided byensuring a continuous supply of slip running into the mould or bywetting the face of the mould before filling. In order to cast under vacuum, it is necessary to havesome sort of vacuum pump, and the necessity of maintainingthe…
Glass
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
