The Geology of Building Stones
by John Allen Howe

Introduction to the 2001 Edition

John Allen Howe O.B.E started his career as a field geologist, first at the Royal College of Science in London, and then with the Geological Survey of Great Britain. However; his preference was for applied geology rather than fundamental research. In 1902 he became curator and librarian of the Museum of Practical Geology, a post he held until 1920 when he was appointed assistant to the director of the Geological Survey, retiring in 1931. It was with the practical aspects of geology that he became most well known and he was particularly involved in the work of the Institution of Mining and Metallurgy, of which he was president from 1942 to 1944 and who awarded him honorary membership in 1949. Even though his later interests tended towards minerals exploration and mining, it is his earliest book, The Geology of Building Stones, for which he is now probably best known.

Although. it is perhaps the medieval cathedrals and castles, together with the stately country houses of the sixteenth and seventeenth centuries, which first come to mind when considering stone buildings, stone was still a major material for both prestigious and domestic projects at the start of the twentieth century. The nineteenth century had been a period of extensive stone building. Projects from the period ranged from Barry’s Palace of Westminster and his Royal Institution in Manchester; both built in the first half of the century, to the great Town Halls of Manchester and other northern cities built in the second half. Even the first example of a ‘New Town’ in Britain, Saltaire in Yorkshire, had been built of stone. By the time Howe joined the Geological Survey, brick and terracotta were being extensively used in addition to stone. Even so, architects such as Sir Edwin Landseer Lutyens, W. R. Lethaby and R. N. Shaw were still using stone. J. L. Pearson’s cathedral at Truro, built of Bath stone and local Mabe granite, was being completed by his son, and work was about to start on the new Anglican Cathedral of Liverpool, designed by Sir Giles Gilbert Scott and to be built in local sandstone. The use of local stone was still relatively common. For example, Lutyens used Bargate stone from the Guildford - Godalming area for many of his country houses in that part of the country

Despite this extensive use of stone, there was no reference work available which provided information on the tremendous range of building stones which had been used in Britain and. perhaps more importantly, were still being produced. The appendices B and C provided by Howe, which list the larger operating sandstone and limestone quarries, give some idea of the scale of the industry at the start of the twentieth century.

As the curator and librarian at the Geological Survey, Howe was in a position to bring together all the information then available not only from the field mapping of the Survey, but also from the building stone collection housed at the museum. Being concerned with the application of geology, he realised that the information on building stone was required by those involved in using the material. As a result, and as he points out in his preface, the book is designed to fulfil the ‘requirements of students of architecture’. Containing a wealth of geological and other scientific and technical data, the book is nevertheless still eminently readable by those with little knowledge of’ geology. Furthermore, it relates the various stones to actual buildings. This is not only valuable in the historical context, but also allows the stone to be seen in use. As all those who have been involved with building stones will attest, there can be major differences between a stone straight from the quarry and the same material after a period of time in a building. In addition, comments on locations where stone has been used, particularly the rarer ones, can be of great help to conservators and architects when attempting to identify stone in a building.

The effect of pollution, frost and organic growth on the breakdown of stone had been recognised in the nineteenth century, and academic research had been carried out on various aspects of this. In 1861 a Select Committee had been established to examine ‘The causes of decay in the New Palace at Westminster’, some of the stone in the new building having lasted no more than about ten years. This report appears to have had few if any practical results. Geologists and other scientists were aware of’ the various factors which could destroy stone and eventually produce soil. The publication of Howe’s book was, however, the first time the subject had ever been brought in any detail to the attention of the users of stone. For the first time architects and others were shown that stone is subject to all sorts of harmful mechanisms, from lichens, to frost, to heat, to pollution, and even to polishing ‘where loafers congregate and sun themselves’. Despite the fact that this study of stone decay was to be superseded twenty two years later by Schaffer’s seminal work on The Weathering of Natural Building’ Stones, the chapter is still a good introduction to the subject. The same can be said for the section on stone testing. in fact, his views on testing were many years ahead of their time. He considers microscopic examination ‘affords a most convenient and reliable means for the investigation of’ the character of a building stone’. There is also a plea for ‘some scheme of Standard Tests. and some organization of authority for carrying out tests regularly and quickly’. Almost a century after these comments were written, Britain is now starting’ to obtain its first standard tests for building stone, in the form of European Standards, including one for petrographic description.

Despite having been written nearly a century ago, the book still remains an extremely important source of information on building stones. Conservators, restorers, architects and civil engineers, will welcome this facsimile reprint as the starting point for any investigation involving the identification of stone in old or historic buildings. it will not necessarily provide instant answers to the type and source of a stone used in a specific building or area, but it will certainly point the investigator in the right direction.

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