210
Views
1
CrossRef citations to date
0
Altmetric
Original Articles

The Early History of Insulated Copper Wire

Pages 453-467 | Published online: 05 Nov 2010
 

In the early 1800s galvanometers could be constructed with the fine gauges of silk-covered copper or silver wires produced for decorative purposes, but when Faraday was making his classic electrical experiments in 1831 he needed a sturdier gauge of copper wire. Bare copper wire was available in many diameters for mechanical applications, but coils for electromagnetic investigations had to be insulated with string and calico. It was soon realized that the cotton-covered springy iron wire then used to hold out the brims of ladies' bonnets showed how copper wire might be similarly wrapped to provide a flexible insulation. The simple manual machines used by the bonnet-wire makers were readily adapted and improved, and a six-head version was built by William Henley. This craftsman's vision of the growing importance of insulated copper wire was abundantly justified, and he built up a large—but poorly organised—empire in the wire and cable trade. Henley's original multiple-head wrapping machine has been located in the Science Museum, London, and the associated silk-covered copper wire subjected to physical, chemical, and electrical testing. For comparison, the electrical conductivity of the ‘mechanical grade’ copper wire used by Faraday has also been determined.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.