An article in the magazine
" The World Of Interiors "

Glass mirrors were introduced in the Roman Empire.Pliny, the elder, in Ist century A.D. tells that glass mirror was invented in Sidon(Now Lebanon).The mirrors tiles at Navdurga Exports are made up of slightly convex and very thin glass cut from blown glass globe coated on the inside with lead.The glassblower first ensures that the surface of the glass batch is clean.He then gathers a small parison on a blowpipe, which is placed near the opening of the furnace to keep it warm. It will be used later in the production. Now the blowing of globes commences. Little by little, glass is gathered on another blowpipe. When the parison attains a weight of a little more than one kilogram, the pipe is handed to a glassblower.

He first heats the parison in the glory hole and blows a globe with a diameter of 50 to 60 centimeters. The globe is then broken off the pipe, leaving a small opening. The globe, resting on the blower’s platform, is turned 180 degrees, and the previously prepared blowpipe is attached to the globe. After the globe is reheated once to smooth the sharp edges that formed when it was broken off the other pipe, it is ready to be coated on the inside with lead.Round ingots of lead weighing one kilogram each are melted in a long- handled crucible. Each ingot will provide enough lead to coat one globe. The coating process itself takes place in front of the furnace. The pontil with the attached globe is lowered into a

hole in the floor, and while the hot globe is rotated, the lead is poured into it. The glassmaker now removes the pontil from the hole in the floor and continues to rotate the globe until the inside is completely coated with lead. The coated globe is placed in a trivet so that the excess lead can run out and be collected for future use. Finally, the globe is broken off the ponti. . Pieces that are too thick or insufficiently coated will simply be re-melted for future use. Because the glass is blown so thin, it is not necessary to anneal it. Then 50 gms of zinc and 50 gms of tin are added to each kg of lead.