Philosophy of technology only came into existence as a specialist branch of professional philosophy during the 1970s, although the philosophical literature during the years between 1945 and the 1970s voices an increasing preoccupation with technology. Just as the First World War led to a wave of disillusionment among intellectuals as well as the common man, so did the Second World War. This disillusionment manifested itself as pessimism, which became characteristic of several influential philosophers during the two first decades after the war. We find it echoed, for instance, in Gabriel Marcel’s The Decline of Wisdom (1954), where Marcel describes the “horror and anxiety” he felt walking through “the ruins of Vienna in 1946, or more recently in Caen, Rouen or Würzburg” (21). But the 1970s, with growing social prosperity, industrial growth, and better technologies, changed that sentiment. The development of a professional philosophy of technology has, after the 1960s, developed along two different yet familiar trajectories: one into an analytical philosophy of technology and science, the other into a Continental (or more broadly humanities-oriented) philosophy of technology (see also Thomson, this volume).

Introduction

This chapter lays out a conservation timeline, from past to future, for the Amsterdam version of Van Gogh's Sunflowers. It starts by considering the restoration history of the painting in order to assess its current physical state, and looks ahead to formulate an appropriate strategy for future conservation treatment and display. Due attention is paid to the two recorded episodes of restoration performed in 1927 and 1961 by the Dutch restorer, Jan Cornelis Traas. Based on physical and chemical investigation of Sunflowers we attempt to reconstruct what these former treatments (which are barely documented) entailed and consider the repercussions for the present condition of the painting. The former interventions by Traas also serve as a benchmark to reflect on current choices made, highlighting the extent to which ideas and methodologies have continued to evolve over the past century as conservation has moved further away from being a singularly craft-based activity to become an established historical and scientific discipline underpinned by ethical guidelines.

Jan Cornelis Traas (1898–1984)

As mentioned, the two main recorded interventions to the Amsterdam Sunflowers may be associated with the Dutch restorer, Jan Cornelis Traas, who treated the picture in 1927, close to the start of his career, and again in 1961, shortly before he retired. Traas was the first restorer to be appointed at the Mauritshuis in The Hague where he worked from 1931 to 1962 and treated hundreds of paintings, including iconic masterpieces such as Girl with a Pearl Earring by Johannes Vermeer. Yet despite the magnitude and importance of his restoration oeuvre, J.C. Traas (as he is usually referred to in surviving documents), has remained somewhat obscure. He is shown here in the only known surviving photograph of him at work, shortly before he retired (fig. 7.1). Unlike his illustrious contemporaries, A. Martin de Wild (1899–1969) and Helmut Ruhemann (1891–1973), for example, Traas did not publish anything, he appears to have kept no records of his work and no personal archive is known. However, the study of some newly discovered historical documents, combined with physical examination of Sunflowers and a large number of other works he treated, allows us to recover an idea of his working practices and approaches viewed within the context of his day.

Introduction

Since its completion by Vincent van Gogh, the Amsterdam Sunflowers has been the subject of a complex history of interventions. Combined with the natural ageing and deterioration of the materials used by the artist, this has strongly affected the present appearance of the painting. The materials and techniques used in Sunflowers and related colour changes have been presented in chapters 4 and 5. This chapter focuses on characterizing the non-original surface layers present as well as secondary compounds arising from pigment-binder interaction in original paint components. The outcomes of this research help to reconstruct the restoration history of the painting and to understand its present condition, as a basis for optimizing future conservation treatment (as elaborated in chapter 7).

In keeping with Van Gogh's usual practice in the period, he left Sunflowers in an unvarnished state. Today, however, multiple layers of varnish are present. These have yellowed and make the painting appear highly glossy, whereas originally it presumably had the more subtle satin gloss related to pure oil paint. Conversely, some areas of the painting now look matt, since wax has been locally applied in the past.

Historical records provide sparse information regarding the surface layers added during earlier campaigns of treatment (see chapter 7). We know that the painting was varnished in 1927 by the conservator Jan Cornelis Traas, as part of a broader restoration and structural (lining) treatment. Remains of paper tape on the tacking margins of the painting are believed to date from this period (see chapter 7, p. 184). Further documents record that in 1961, Traas worked on the painting again. However, as there is no known account of what this treatment entailed, it remained in question whether Traas removed the 1927 varnish and/or applied new surface coating layers instead. Furthermore, in the late twentieth century, wax was applied in certain areas, used to matt down the glossy varnish and/or impregnate and consolidate the ground.

This chapter describes the outcome of the technical examinations of the Amsterdam Sunflowers, characterizing the surface layers present and assessing the history of application as revealed by their stratigraphy and chemical composition.

Executive summary

Nature of the problem

• Biodiversity is the variability among living organisms, from genes to the biosphere. The value of biodiversity is multifold, from preserving the integrity of the biosphere as a whole, to providing food and medicines, to spiritual and aesthetic well-being.

• One of the major drivers of biodiversity loss in Europe is atmospheric deposition of reactive nitrogen (Nr).

Approaches

• This chapter focuses on Nr impacts on European plant species diversity; in particular, the number and abundance of different species in a given area, and the presence of characteristic species of sensitive ecosystems.

• We summarise both the scientific and the policy aspects of Nr impacts on diversity and identify, using a range of evidence, the most vulnerable ecosystems and regions in Europe.

Key findings/state of knowledge

• Reactive nitrogen impacts vegetation diversity through direct foliar damage, eutrophication, acidification, and susceptibility to secondary stress.

• Species and communities most sensitive to chronically elevated Nr deposition are those that are adapted to low nutrient levels, or are poorly buffered against acidification. Grassland, heathland, peatland, forest, and arctic/montane ecosystems are recognised as vulnerable habitats in Europe; other habitats may be vulnerable but are still poorly studied.

• It is not yet clear if different wet-deposited forms of Nr (e.g. nitrate, NO3− versus ammonium, NH4+) have different effects on biodiversity. However, gaseous ammonia (NH3) can be particularly harmful to vegetation, especially lower plants, through direct foliar damage.

• […]

Executive summary

Nature of the problem

• Observations of atmospheric reactive nitrogen (Nr) deposition are severely restricted in spatial extent and type. The chain of processes leading to atmospheric deposition emissions, atmospheric dispersion, chemical transformation and eventual loss from the atmosphere is extremely complex and therefore currently, observations can only address part of this chain.

Approaches

• Modelling provides a way of estimating atmospheric transport and deposition of Nr at the European scale. A description of the different model types is provided.

• Current deposition estimates from models are compared with observations from European air chemistry monitoring networks.

• The main focus of the chapter is at the European scale; however, both local variability and and intercontinental Nr transfers are also addressed.

Key findings/state of knowledge

• Atmospheric deposition is a major input of Nr for European terrestrial and freshwater ecosystems as well as coastal sea areas.

• Models are key tools to integrate our understanding of atmospheric chemistry and transport, and are essential for estimating the spatial distribution of deposition, and to support the formulation of air pollution control strategies.

• Our knowledge of the reliability of models for deposition estimates is, however, limited, since we have so few observational constraints on many key parameters.

• Total Nr deposition estimates cannot be directly assessed because of a lack of measurements, especially of the Nr dry deposition component. Differences among European regional models can be significant, however, e.g. 30% in some areas, and substantially more than this for specific locations.