R E V I E W A N D A N A L Y S I S 45 text books and museums solely as remarkable examples of ‘very old’, or ‘very rare’, or ‘very beautiful’ things – objects that inspire awe on account of their scarcity, having existed for a long time, or the craftsmanship that they embody. But they earn their place in our hearts by a very different route. Physical heritage provides a vital backdrop to our human experiences and an anchor point for our personal and collective memories. Our shared experience of it helps to put the pattern of our lives in context and provides an important mechanism through which we can relate to others, individuals, communities, whole societies whom we may or may or not have ever actually met. Rather like a physical book is a repository for a set of ideas with which a community of readers form meaningful relationships, heritage objects are pan-generational repositories for spiritual and emotional glue – ties that bind people together across geography and time. And so, attacks on cultural property are attacks not only on material realities but human ideals: it is for this reason that they move us to tears. Since the destruction of Palmyra, a number of important digitaldomain projects have been created, seeking in different ways to draw attention to the damage to the site and its importance to the people of Syria. Initiatives include a number of virtual reality modelling projects (see the New Palmyra Project, www. newpalmyra.org), several digital archiving programs (see the Syrian Heritage Project, https://arachne. dainst.org/project/syrher), and a project to create a digitally-milled large-scale reconstruction of the site’s triumphal arch undertaken by the Institute for Digital Archaeology (IDA) (as discussed by Stuart Burch in ‘A Virtual Oasis: Trafalgar Square’s Arch of Palmyra’, published in the International Journal of Architectural Research, volume 11, issue 3). The original triumphal arch, shown on page 44 was built in the 3rd century AD while Palmyra was under Roman rule. Architecturally, it is a beautiful example of the fusion of eastern and western styles for which Palmyra has long been admired: it is instantly recognisable as a Romanstyle arch but it is decorated with the swirling foliage and flowers typical of ancient Persia. It was reduced to rubble in October 2015 (page 44). The IDA project employed advanced photogrammetry and a state-of-the-art 3D machining technique that allows digital computer models to be translated into physical structures using original materials – in this case, stone. The whole process, from the beginning of the digital modelling phase to the end of the construction phase, was completed in ten weeks. In the first stage of the project, crowd-sourced photographs of the original arch, taken prior to destruction, were used to create a three-dimensional digital model (above). Continuing in software, this model was then solidified and transformed into an engineering assembly comprising seven individual parts interlocking through a system of concealed steel pins. Each of these parts was then machined from a solid block of Egyptian marble by project partners Tor Art (above right) using robotic equipment adapted from that used on automotive assembly lines. The finished structure is 18 feet high and was first unveiled on London’s Trafalgar Square by the then mayor of London Boris Johnson and the then director general of antiquities and museums in Syria, Maamoun Abdul Karim, on April 19, 2016. The arch attracted large crowds in London, but more significant than the foot-traffic alone was the extent to which the people of London welcomed it as a means to express collective solidarity with the Syrian people. The arch began to take on a life of its own as a kind of monument in its own right – a symbol of hope over despair and of cooperation over conflict. Five months after the London installation, the structure was erected on New York City’s City Hall Park. The arch then travelled to Dubai in February 2017, followed by Florence in March for the G7 Culture Summit (overleaf ). It then spent the summer in the Italian town of Arona where its installation was organised as a tribute to Khaled al-Asaad (overleaf), and its most recent installation was in September 2018, on the National Mall in Washington DC. Three years into the project, almost 5 million people have now visited the arch in person and hundreds of millions have seen the installation through television, radio, Work in progress. A three-dimensional digital model of the triumphal arch was constructed by photogrammetry using crowd-sourced photographs of the structure taken prior to its destruction. Each of the seven parts of the IDA’s reproduction arch were robotically machined from a solid block of marble by project partners Tor Art in Carrara.