BCD 2017

88 T H E B U I L D I N G C O N S E R VAT I O N D I R E C T O R Y 2 0 1 7 manufacturer also relates to his connection with important designers: JB Papworth, Sydney Smirke and John Bacon Junior were among those who used his services and designed his castings. William Ranger (1799–1863) was another artificial stone producer who patented his process (1832 and 1834). He, however, preferred to use relatively weak hydraulic limes, relying on quick lime, hot water and mould compression to harden his products, which were mainly architectural and included a range of forms such as ashlar blocks, column sections and capitals. Similar traditions also developed in other European countries such as around Grenoble in France where a natural cement was being produced. The main aim of most early producers was to imitate natural stone and to find a binder that could match the surface and colour of Portland or Bath stone. Later in the 19th century the use of coloured and pigmented artificial stone was more common, and precast building systems began to appear, such as William Lascelles’ ‘patent cement slab system’ (patented in 1875). GARDEN AND LANDSCAPE ORNAMENT During the mid-19th century the fashion for garden landscaping, grottoes and ferneries led to the adoption of ‘artificial rockwork’. The best known producer was Pulham and Son, who developed a cement-based system in imitation of natural rocks called Pulhamite Artificial rockwork. This was first used during the 1840s but really developed in the mid-to-late 19th century, with some large schemes being carried out at Highnam Court, Gloucestershire (1847–62), Battersea Park (1865–70) and Madeira Walk, Ramsgate (1894). The first James Pulham (1793–1838) developed his skills while working for William Lockwood in Woodbridge, Suffolk, but it was the second James Pulham (1820- 1898) who was responsible for the rapid development of the business for much of the 19th century. The business closed around the start of World War II. The Pulhamite Rock-Work system was described by Pulham (in A description of a Naturalistic Pulhamite Fernery, Conservatory, or Winter Garden ) as: ‘the building up of natural stone in complete imitation of a portion of rocky cliff with stratified or unstratified stone or rock, and joined, where necessary, with Pulham’s cement, made of the same colour and texture, as lime or sandstone, and tufa. Where no real stone or rock exists, at or near, and too expensive to get then the Pulhamite formation is adopted. The core is formed by building up burrs, rough bricks, rubble etc, to the rude rocky shapes; then covered with cements of the colour, form and texture of the rock, which may be considered to be the most natural or nearest to the locality. Sometimes real rock or stone is used with artificial, for economy and effect; in thin strata, where large blocks of real stone are too expensive, this adds to the naturalness of the appearance, and not too much cost’. Frequently hydraulic lime was used as the masonry construction mortar, and a series of large cantilever stone slabs, often entirely covered with the Pulham cement mortar, was used to provide projecting plant pockets and strata. Rock embankments and walling could include small sandstone lintels buried below the surface, off which further masonry walling was constructed. In grottoes, the use of natural limestone such as tufa was common, bonded to the walls with Roman cement and the areas between were made up with colour- matched mortar (often hydraulic lime based), thrown on to give a suitable rough texture. MATERIALS, PROCESS AND TECHNIQUES The rapid and exciting developments in cement binders in the first half of the 19th century were often reflected by developments in the artificial stone workshops. For example, an article by John White on cementitious architecture in the Dictionary of Architecture (see Further Information) states: ‘Austin’s Artificial Stone, a composition invented by Mr Austin, of New Road, London [was used] about the year 1814, when Roman cement formed the chief ingredient: Atkinson’s cement was employed about five years later, and about 25 years since Portland cement was adopted, which material is still used by his successor, Mr Seeley’. The impetus for these changes was the requirement to have cast products which looked like natural stone, and the predominantly brown colour of Roman cement was not popular in this respect, although it remained a useful material in hidden locations. Atkinson cement, also known as Yorkshire or Mulgrave cement, was a natural cement derived from Sands End in Yorkshire which was much less brown and more grey in colour. The fore-runner of modern Portland cement, Aspdin’s Portland Cement (patented 1824) was named after the stone it was intended to imitate. This journey through the various binders of the period is reflected by other users as well. Lockwood was a manufacturer of Roman cement but later (c1820) developed his Portland Stone Cement, probably based on eminently hydraulic lime from South Wales. By contrast, both the Pulhamite Artificial Rockwork and later 19th-century artificial stone often used pigments to colour the pale cement binders to provide the necessary imitation. In Pulhamite rockwork, mortars of different pigmented colour were carefully manipulated and applied by hand to imitate the variations of colour found within the rock face and strata. This is not always immediately obvious because the rockwork is often now covered in algae, moss, or other deposits. As well as pigments, the Pulhams also used mortar inclusions such as shells, or impressed designs which imitated fossil bands for example. The later 19th-century artificial stones tended to be more frequently pigmented with reds and browns, no doubt in imitation of red sandstone or even terracotta. In some cases items have been intentionally painted either as a decorative façade treatment or in an effort to replicate the item portrayed. Examples of the latter include the dinosaurs (by Benjamin Waterhouse Hawkins) at Crystal Palace, Sydenham and garden statues prepared in cement for Joseph Paxton for Crystal Palace in the mid-1850s. Aggregates could also make an important contribution to the colouring and surface texturing of early artificial stone. Austin’s characteristic mortar matrix (sometimes referred to as ‘puddingstone’) provides the necessary surface colour and texture of his products. His mortar composition includes extensive quantities of crushed Portland stone ranging in size from less than 1mm up to 10mm. When the original surface – which tends to be fine-textured – is weathered, the larger aggregates of Portland stone can be seen to stand proud of the cement matrix. This is often one of the indications that the material is a historic artificial stone product. Minor quantities of other stone types are also found in the matrix but these are generally regarded as contaminants occurring during processing. The yard of Austin and Seeley in the late 19th century showing the wide range of sculpture available in artificial stone (Reproduced by permission of Historic England Archive) Drawing of sculpture commissioned by Joseph Paxton for a fountain at Crystal Palace, Sydenham in 1854 (by kind permission of the Crystal Palace Foundation) and, below, one of the surviving sculptures (Photo: C Dunkley)