Historedia
Episode 4 of 4

Cable Failure in September 1858

When
September–October 1858
Where
Valentia Island
Part of
The first transatlantic telegraph cable is completed and fails

The cable failed due to insulation deterioration, ending its short-lived operation.

In September 1858, the cable failed altogether after several days of progressive deterioration of the insulation. It was particularly vulnerable in the first hundred miles from Ireland. Operation was terminated on October 20, 1858, due to this malfunction.

Sources

  1. Transatlantic telegraph cable Wikipedia, revision of 2026-07-15
  2. Heart's Content, Newfoundland and Labrador Wikipedia, revision of 2026-09-06

Machine-drafted from the cited Wikipedia passages and checked by a reviewing model, not by a human editor. Every passage cites the revision it was written from; dates and places follow those passages.