|Archive of Monthly News Items|
As previously featured in the History Centre
April - June 2008
Railway stations naturally had clocks but they couldn't keep accurate time over days and had to be regularly reset. The larger stations could get a time check via their telegraph system. It was to meet the need of other stations that, in 1904, George Gibbs developed his heliochronometer. He started production in partnership with William Pilkington. There is no record of how many were made. The serial number of each unit was stamped on the base and numbers so far discovered suggest production may have barely reached a thousand. Unfortunately the number on ours is no longer legible. The problem of accurate nationwide timekeeping was ultimately solved when the BBC started broadcasting the time signal in 1924.
Each unit had to be carefully set up, relative to its longitude and latitude. Thereafter operation was fairly straightforward. Heliochronometers are still produced today. A series of pages here shows how they work.
The chamber kiln on the Medina site is thought to be one of only two examples remaining in the country, both in a dilapidated state. The other example, in Kent, is of a known design, whereas the Island structure cannot be fully explained, at least not without some excavation. The main east-west section seems to represent the original Johnson chamber kiln layout, apparently initially brick-built but subsequently enlarged with concrete. The puzzling element involves a series of firing units along the south side. These cannot yet be explained in relation to the rest of the structure. In the 1870s a young engineer, Vitale de Michele, was the driving force in developing the company's industrial processes. Michele eventually patented his own variation on the Johnson kiln, so it's not beyond the realms of possibility that the unique layout of the Medina kiln formed part of his experiments.
Ironically it's the 'preservation' of the Medina kiln that's likely to put it beyond future excavation. As long as it had public access it was kept relatively clear. Now that it's contained within an ecological site it has already become heavily overgrown, with some of its more subtle features no longer visible. The kiln has been included in the 'Local List' but this appears to have no bearing on its future.
The local authority's approach to the kiln cannot be expected to do more than reflect a national indifference towards this forgotten industry. There is virtually no professional expertise they can call upon. The Museum of London Archaeology Service were commissioned to carry out a survey of the structure but, although they studiously recorded the build, their lack of experience in the subject resulted in confused terminology and interpretation. Understandably, they made no attempt to explain how the kiln worked. The nation's heritage institutions were latecomers to industrial archaeology. In the case of the cement industry, they were simply too late.