The 'Rocket' of the lighthouse world: the Fresnel Optic of Hartlepool Heugh Lighthouse and its gas light – a 'missing link' in burner development.

Robert Stephenson's 'Rocket' was the first of its kind and intentionally preserved as an icon of railway history. The Fresnel fixed optic at Hartlepool was the last of its kind and was preserved by accident. Nevertheless, like 'Rocket' it is an extraordinary survival of an artefact representing a seminal moment of a technical achievement which had a lasting influence. It thus no less an icon than the famous locomotive. Hartlepool Heugh Lighthouse was built in the mid-1840s and lit by an optic and a gas lamp, seemingly a unique combination. The burner was apparently a completely new type, producing a flame large and steady enough to exploit the refracting and reflecting characteristics of the optic, something no previous gas burner had been able to achieve. The paper considers the optic and its lamp in the context of contemporary developments in lighthouse illumination and burner design and gives an account of the history of gaslit lighthouses before Hartlepool. The construction of the lighthouse provoked a clash between the Port authorities and Trinity House and the reasons for this are examined. The optic had an astonishingly long life of nearly 80 years, remaining in service until 1927, by which time it was perceived as an historic object which should not just be discarded. The paper concludes with the story of its preservation and subsequent display by the Hartlepool Museum service. [ABSTRACT FROM AUTHOR]