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These lamps shown above are tantalum filament lamps.  Tantalum filaments were introduced in 1906 with the 44-watt light bulb.  The 44-watt lamp was later discontinued and replaced with 40-watt and 80-watt lamps for a 110-volt circuit.  These lamps were used mostly for DC (or Direct Current) circuits, of which only a few cities provided at the time these lamps came out.  Most other cities at the time were using AC (or Alternating Current) circuits for the homes.*  Hence tantalum lamps were sold in low quantities and production of these lamps did not last very long.  After seven years on the market, the lamps were discontinued in 1913.  Because of this very short period of use, tantalum lamps are quite rare.

* Today, all homes in this country are provided with AC or Alternating Current.”

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