C O N T E X T 1 3 3 : M A R C H 2 0 1 4 5 Periodically After the drought (passim), the deluge! The journals that did not arrive promptly in time for the last Context deadline have been piling up since. As there is much of interest and much to cover, some of the reports here will be a little brief. Issues of the Association of Preservation Technology bulletin, the Journal of Preservation Technology, are always eagerly awaited. Two arrived shortly after one another in November. The content of the middle (double) issue of 2013 (Volume XLIV, Nos 2–3) was wide ranging.While much of the institute’s focus is on professional skills, Gerard Lynch provides a useful reminder of the importance of craft skills predating architecture as a distinct profession, and the current need to reposition craft education, strengthening the links between the skills of the artisan and the skills of the architect at a time of acute shortage of traditional expertise. Soft capping the masonry walls of ruined structures is seen as a potentially less damaging alternative to cementitious hard cappings. Trials conducted by English Heritage in Northumberland were reported in the Journal of Architectural Conservation in March last year. Similar techniques are being applied to exposed archaeological sites in the USA at Mesa Verde, Colorado, where the climatic conditions ornament in the later part of the 19th century and the early part of the 20th. The content brings together papers presented at a symposium on the history and characteristics of these materials held at Columbia University, New York, in March 2011. The participants, drawn from a wide range of heritage disciplines, considered issues of appropriate conservation, repair, restoration and replacement. The great champion of cast-iron buildings, particularly in the SoHo neighborhood of Lower Manhattan, was Margot Gayle. In the opening article Carol Gayle and John GWaite celebrate her dedication and determination in saving so many (then) under-regarded structures. A very helpful article by Richard Pieper covers a rough checklist of the nine key issues to be considered when undertaking architectural cast-iron restoration together, and a brief introductory overview of the history of the preservation of both cast and wrought iron. One of the great charms of heritage work is poring over the compendious 19th century catalogues of architectural ironworks and the accompanying sadness that almost all these traditional firms are now extinct. It is therefore valuable and encouraging to be reminded by J Scott Howell that patternmaking for architectural castings has entered the digital age by way of 3D laser scanners, modeling software and 3D routers, thereby using modern technology to ensure accurate replication. Although structural ferrous metals were largely superseded by the 1920s and are often referred as ‘archaic’, they still exist widely in historic buildings and are susceptible to modern strength assessment by rationally applying modern structural engineering methods. These are clearly explained in an article by Conrad Paulson, who addresses the challenges of identifying the strength characteristics and appropriate treatment strategies. He demonstrates how variables embedded in early, nonstandardised production processes shaped their structural performance. are rather more extreme. An article by Alex B Lim, Frank G Matero and Michael C Henry explains the technique from an American perspective and the encouraging results of the cappings as an effective and versatile protection method. The authors warn of the need for context-specific adaptation to the site and the consideration of variables such as water loading from precipitation and snow melt, thermal and convective action needed for evaporative drying, and the selection of non-damaging vegetation. Other articles with a more North American bias cover the structural assessment of historic timber railway piles on the banks of the Mississippi in Minnesota; the use of traditional skills to repair or stabilise traditional construction in Hawaii following the 2006 earthquake; an assessment of the significance (particularly for construction history) of the ‘world’s largest’ all-reinforced-concrete office building, the 12-storey, 1910 Plymouth Building in Minneapolis; and the evaluation of historic commercial unreinforced masonry buildings in earthquake-prone Seattle. The Journal of Preservation Technology is known for its advocacy of diagnostic technology. It is worth highlighting an article by Nicole Trujillo, Thomas E Boothby and Erik Valentino on the use of air-coupled, impact-echo, non-destructive testing for flaws in masonry such as cracks, delaminations, voids, honeycombing and debonding. This evaluation is done by monitoring the surface motions derived from a short duration mechanical impact and measuring surface displacement from the stress waves this generates. Two field test examples are described, one fromWyoming Seminary in Kingston, Pennsylvania, and the other from Beverley Minster inYorkshire. The last issue of the Journal of Preservation Technology for 2013 (Volume XLIV, No 4) is devoted to those most versatile of architectural materials, cast and wrought iron, particularly popular in the United States for cladding and architectural
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