Agricultural History Review, Volume 67 Part 1 (2019), p. 145

Lime kilns are among the commonest industrial archaeological sites in the British landscape and are by no means restricted to limestone country. In this attractive slender volume, David Johnson, who has researched lime kilns in northern England extensively over many years, provides an overview of the development of lime kilns (mainly but not exclusively in a British context) from the earliest times to the present day. It offers a useful guide to these often unnoticed legacies of the past for all who are interested in the history of the rural landscape.

Lime was a ubiquitous part of life in rural Britain for many centuries, not only as the soil sweetener so central to the era of Improvement but also as the key ingredient in mortar for building and as a constituent of processes as diverse as tanning, bleaching and paper-making. In order to obtain quicklime from raw limestone or chalk, the stone was broken into small pieces and ‘burnt’ with fuel in a kiln in order to achieve the process of calcination, which removed moisture and gasses and changed its chemical composition. Though the form and complexity of kilns evolved across the centuries, the process remained essentially the same.

The bulk of this book takes the form of a chronological canter through the development of kilns from the Romano-British and medieval centuries to modern times. Many early kilns, often surviving as little more than a slight depression in a pasture, were clamp kilns in which the limestone and fuel were sealed using turf or clay. Such were the crude ‘sow’ kilns found in the Yorkshire Dales, some of which have been shown by excavation to have been medieval in date, though the same simple technology continued to be used for new kilns until the 1850s.

More numerous are the stone-built field kilns which proliferated during the era of land improvement and enclosure during the eighteenth and nineteenth centuries. Often set into a hillside near an outcrop of limestone, they can be recognized by the tell-tale stone-arched draw hole from which the finished lime was shovelled. Ordnance Survey maps show that there were thousands of field kilns in the mid-nineteenth century. Kilns tended to grow larger over time, allowing higher temperatures and greater quantities of lime to be obtained.

Kilns of this era were by no means restricted to limestone and chalk country. A major coastal trade in lime developed, involving both the shipping of raw limestone or chalk to areas which had none and the trading of quicklime. This resulted in kilns being built in coastal locations, both along the western seaboard from Devon and Cornwall through Wales to western Scotland and on the North Sea coast in East Anglia (to which chalk from Kent was transported) and in Northumberland (from which lime was sent to eastern Scotland).

The later chapters trace the evolution of large commercial lime kilns across the nineteenth and twentieth centuries. It is a story of the quest for improved efficiency, economies of scale and a higher-quality end product. Most were located close to large commercial quarries and produced lime on a scale altogether more massive than the field kilns. Batteries of kilns were built, serviced by mineral railways and tramways, both to feed the kilns and to transport the finished lime. Increasingly complex vertical kilns were devised, with sophisticated air flows to optimize efficiency. Equally sophisticated were the horizontal continuous kilns, such as the Hoffmann kilns, where a ring of twelve or more firing chambers around a central flue enabled continuous production of lime. Dr Johnson brings each of these phases in the history of lime kilns alive through descriptions and illustrations of specific sites, thus weaving a wealth of local detail into the text.

The book is topped and tailed by brief excursions into the culture of lime kilns, both in art and literature and as modern ‘heritage assets’. A helpful bibliography provides a guide to further reading for those who wish to pursue the subject in greater depth.

This is a welcome addition to Amberley Publishing’s list of richly illustrated books which aim to appeal to a wide readership and to provide authoritative introductions to a topic. Amberley is continuing the tradition established by the erstwhile Shire ‘albums’, ‘Archaeology’ and ‘Discovering’ series, in publishing pithy introductions to archaeological and historical topics in the form of attractive slim books of around 15,000 words and 100 or more illustrations. It is a format which enforces brevity, with the result that the reader is sometimes left wishing that some sections could have been fuller, but, as David Johnson’s book demonstrates, it can work well to provide a short, illustrated introduction to a subject with which a reader is unfamiliar.