How was the light bulb built?

Answer 1

Early bulbs were made of glass, blown into a bulb shape, using techniques already common in making glass drinking vessels and ornaments.

The filment is inserted at the open end and the glass re-heated to form a seal.

The air is drawn out using a suction pump, either attached at the same free end or through the opposite end via a tube. The glass being re-melted to keep a vucuum inside the bulb.

Early experiments in making the bulb, made bulbs in the form of a football, with a point at both ends, where the air has been drawn out.

It is important to remove the air, to stop the oxygen burning up the filament as it glows white hot. Modern bulbs replace the air with an inert gas, which does the same job.