Artifact #2

DISCOVERED

After a Century in Darkness

Edison Trial Evidence Collection

"Edison Electric Light Company vs. United States Electric Light Company"

Tar-putty Lamp No. 2

Tar-putty Lamp label - No. 22

Tar-putty Lamp No. 2 is also labeled Tar-putty Lamp Exhibit No. 22

"Edison Electric Light Company vs. United States Electric Light Company"

Tar-putty Lamp #2 has an eleven loop filament of perfectly uniform coiled turns formed from a strand of Tar-putty approximately 0.007 inch in diameter carbonized in a single cylindrical helix shape approximately 1/8 of an inch in diameter and 3/8 of an inch wide.

This famous Tar-putty lamp has two paper labels. The label located near the evacuation tip (tit) is a quartered court square and has a hand written "2" in the center, the number coinciding with its position in the pigeon hole compartments of the wooden box. The older courtroom exhibit label is located near the base of the lamp and is marked in dark ink with the number "22" marked out by pencil.

Lamp #2 is one of the seven Tar-putty lamps found in the Historic Edison Collection. Each Tar-putty lamp was made in 1890 by Edison's key witness, J. W. Howell, made as exhibits in the Edison patent suit, "Edison Electric Light Company vs. United States Electric Light Company." In this renowned courtroom drama Edison's rivals were winning the legal war right up to the moment of 11:00 AM, July 8, 1890, the moment of Howell's testimony when Edison presented these lamps as evidence.

In the world of intellectual property law, this Tar-putty lamp evidence is the most important patent exhibit ever proffered in the courtroom.

The seven Edison Tar-putty lamps in this collection are the only lamps of their kind known to exist that are documented as being Edison's courtroom evidence. This is the evidence that won the most famous technology infringement trial in history.

John Howell made this filament to match the Patent Office Model lamps: (Edison's Menlo Park 1881 Lamp "8", Edison's Menlo Park 1881 Lamp "9", and Edison's Menlo Park 1881 Lamp "10").

Transcript Volume V, pg. 3505 - Deshler testimony about Tar-putty lamp No. "22"

2007 is this lamp's 117 th. Anniversary

Go To the Collection Group Exhibit

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