Tree-ring dating, is one of the few scientific testing methods available to help authenticate violins, says John Dilworth
Until the mid-1990s, violin experts thought they had a pretty good understanding of the Brescian school. The distinctive work of Gasparo da Salò and Giovanni Paolo Maggini, for example, is well known and thoroughly catalogued, and documents such as tax accounts and censuses have yielded bountiful information about these makers’ lives. Yet dendrochronological tests accumulated over the past decade have thrown up startling revelations about a particular late body of work that had been comfortably attributed to Maggini: some of these instruments could only have been made after his death.
I first became aware of the use of dendrochronology in stringed-instrument authentication in 1995, while working alongside Roger Hargrave and Stewart Pollens on Peter Biddulph’s exhibition, The Violin Masterpieces of Guarneri ‘del Gesù’, at the Metropolitan Museum of Art, New York. Pollens had invited the dendrochronologist Peter Klein of Hamburg University, whose investigations of wooden boards used by Rembrandt helped to establish a catalogue of the artist’s work. It was a revelation that the technique could be applied to violins.
We learnt a great deal from Klein, not merely that all the instruments in the exhibition had valid dates (to our relief) but also that spruce pieces matched each other from instrument to instrument, and that some ‘del Gesù’ instruments contain wood with surprisingly short seasoning times. Contrary to the view that ‘golden age’ violin makers regarded old wood as key to making good instruments, we found that ‘del Gesù’ used wood that was still almost fresh from the forest.
Dendrochronology works by matching the variation between growth rings – the grains of the spruce in the case of violins – to historical climactic conditions by fitting the pattern of growth to the database of seasonal weather changes over thousands of years. Analysis of the results reveals the dates of the grains in the violin’s front and establishes the most recent date that the tree was still growing. For determining authenticity or otherwise, the results merely have to show that the last dated growth ring occurred during the lifetime of the supposed maker. The great advantage of the technique is that it uses observational data, not destructive sampling: the instrument is photographed in high resolution and the variations in grain width recorded. No material is removed or interfered with.
Until dendrochronological tests proved otherwise, nobody had doubted that the instruments attributed to late Maggini were anything else. When it transpired that the wood used for the fronts of certain instruments was still growing in the tree long after Maggini’s death in 1632, there was obviously some revision to do. These violins are authentic master instruments, but ones we can no longer attach a name to with certainty. It may be that Maggini had a son or apprentice who maintained the shop after his death. Others suggest that these later works were made by G.B. Rogeri in Brescia in an imitation of Maggini’s Brescian style.
Dendrochronology has had a generally stabilising effect on authentication, and in many cases has provided – for the first time – forensic backing to traditional authentication: the eyes and ears of the connoisseurs who have made uncannily accurate assessments of historical work. The science has also provided valuable information to modern makers: the patterns of use of specific trees from specific forests by different luthiers in different locations; the trees shared by makers in different countries; the use of relatively fresh rather than long-aged wood, and so on. All these findings shake up tired ideas about ‘Little Ice Age’ wood and bizarre seasoning techniques. The more the data accumulates, the more detailed and interesting the picture becomes. It is only a matter of time before all instruments with an attribution undergo dendrochronological analysis, for it is one of the few scientific tests available to the violin expert that can be easily and usefully applied.