Neale's Patent
This quite plain looking insulator is known as Neale's pattern line insulator.
Mr Neale was the Head of Signals and Telegraph for the North Staffordshire Railway (NSR), centred around Stoke-on-Trent and introduced this pattern in about 1880, continuing in use until about 1965.
Bullers coded this E.I.458 in their catalogue of the late 1880's
Taller and thinner than a Standard Post Office pattern cordeaux early examples were cemented to pins and later ones were changed to a screw thread.
Image courtesy of Jim Gough