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These are squirted cellulose filament lamps with plaster of paris bases manufactured from about 1893 to 1900.  Squirted cellulose filaments were manufactured by dissolving cotton in a solution to form a syrupy mixture that was then forced or “squirted” through an orifice or die straight into another solution of alcohol, which served to harden the squirted filament.  The resulting strengthened filament could then be wound on drums and cut to any desired lengths and then carbonized.  (The length of split bamboo filaments, on the other hand, could be no longer than the distance between the joints of the bamboo cane.)  With their lower specific resistance, these filaments had to be very long in order to give off much light.  Thus the final configuration may be one single very long hairpin filament, two hairpin filaments connected in series, or one filament having a loop, which was either anchored to the stem or spiraled.  All of these filament configurations could be mounted inside either a pear shaped bulb or a straight-sided bulb.  Some of the bulbs with squirted cellulose had skirted bases [see A23] to allow the wide and large filaments to fit into the bulb and also dissipate the extra heat generated by the longer filaments.  From 1893 to 1900, squirted cellulose lamps were manufactured with plaster of paris bases.  In 1900 a few of them were manufactured with porcelain bases.  From 1901 to 1918 they were manufactured with glass bases.  Manufacturing of all squirted cellulose lamps ceased in 1918.  The three bulbs shown above were manufactured in 1893, 1894, and 1898 respectively.

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