Artifact #1

DISCOVERED

After a Century in Darkness

Edison Trial Evidence Collection

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

Tar-putty Lamp No. 1

Tar-putty Lamp label - No. (1) 10

Tar-putty Lamp No. 1 is also labeled Tar-putty Lamp Exhibit No. 10

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

Tar-putty Lamp #1 is one of the seven Tar-putty lamps found in the historic Edison Collection. Each Tar-putty lamp was made in the spring of 1890 by Edison's key witness, John W. Howell, made specifically as exhibits in the famous Edison patent suit, "Edison Electric Light Company vs. United States Electric Light Company."

This Tar-putty lamp has two paper labels. The label located near the evacuation tip (tit) is a quartered court square with a hand written "1" 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 "10" (crossed-out by pencil marks) anf the number "1" in pencil.

Each Tar-putty lamp has a coiled filament made of lamp black and tar in accordance with description in Edison's fundamental lamp patent, U.S. Patent 223,898. In his 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 John Howell's testimony when Edison presented these Tar-putty filament lamps as evidence to prove to the court that Edison's patent was valid.

For a patent to be valid a person schooled in the art must be able to construct a working example of the invention using the patent as the only instructions. John W. Howell proved exactly that point when he made these Tar-putty lamps for evidence, which proved the Defendants wrong. 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.

Transcript Volume V, pg. 3505 - Deshler testimony about Tar-putty lamp No. "10"

2007 is this lamp's 117 th. Anniversary

Go To the Collection Group Exhibit

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