It was not without some hesitation that I agreed to write a review of this book. For years, David and I had worked – admittedly with a different focus – on the Bauer brothers, partly in parallel (Mabberley 1999; Lack 2000, 2008), partly in collaboration (Lack with Mabberley 1999), and recently I summarized my research in a monograph covering the lives and works of all three brothers, i.e. Joseph, Franz and Ferdinand (Lack 2015). Would David come to entirely different conclusions and, if so, would I not be too biased to write a proper review?

In a sense, “Painting by numbers” is a second, revised version of David's 1999 book with basically the same structure and the same emphasis on Ferdinand's documentation of the Australian flora and fauna as compared to his earlier work done for Norbert Boccius and that on the flora and fauna of the Levant done for John Sibthorp. The new book is also substantially enlarged, the number of pages almost doubled and the format slightly larger. Unsurprisingly, several illustrations have also been taken over from the earlier book. However, in a sense – and this is reflected in the new title – it is also a new book with much more attention given to Ferdinand's colour-coded pencil drawings, of which several are published here for the first time. In addition, David has taken pains to integrate most of the new information published in my 2015 book and that which became available later, e.g. a report in Antiques Trade Gazette 2262 (2016), or which I had not considered, e.g. Rhizopoulou's paper in GlobalNESTJournal 14 (2012) on Ferdinand's Levantine views and the changes in the Mediterranean that have happened since his travels in 1786–1787. For good reasons, David, in contrast to other biographers like Marianne Klemun and Helga Hühnel in their recent biography of Nikolaus Joseph Jacquin, follows conventional chronology, which almost always makes a good story and is easy to follow; his style is lucid and a joy to read. An example may illustrate this point – Sibthorp, newly appointed third Sherardian Professor of Botany at Oxford University and one of Ferdinand's masters “was to brush aside whatever local duties were attached to his new post, for … he abandoned Oxford to go travelling once more [in fact, for more than three years]” (p. 24). In addition, David can rely on a broad understanding of the lives of Sir Joseph Banks and, in particular, Robert Brown, Ferdinand's travel companion and superior on the Investigator voyage, a fact felt in particular in Chapters 5 “Perfecting the technique: the Pacific” and 6 “Terra Australis circumnavigated”. The verbatim quotations taken from the diaries of Brown, Peter Good, Samuel Smith and Mathew Flinders's travel report as well as Ferdinand's letters make good reading and offer a wealth of detail on the circumstances of the expedition, e.g. the mass slaughter of Macropus fulginosus fulginosus on Kangaroo Island (p. 93) or the collecting of very many specimens of Chelonia mydas on Bountiful Island (p. 113) for food. New information, partly collected from entries in the Sydney Gazette, is provided on Ferdinand's subsequent stay in and around Sydney, where he lodged at Anson's Farm, now the site of the Royal Botanic Garden and Domain.

There are a few mistakes, but they do not touch upon the core of the story: the castle at Feldsberg (today Valtice, Czech Republic) was not confiscated by the Nazis (p. 3), but was used during the Second World War as one of the temporary depositories for the art collections of the Reigning Prince of Liechtenstein; the famous colour chart kept in the archives of the Real Jardín Botánico, Madrid has a published precursor, although that used letters instead of numbers (p. 9); van Swieten did not invite Jacquin to travel to the islands in the Caribbean Sea (p. 14), but it was Francis I, Emperor of the Holy Roman Empire, who wrote the instructions for Jacquin in his own hand; Tournefort's findings were at that moment (i.e. 1786) not being published in Paris (p. 27), but this process started only in 1808; Hypericum calycinum was not sketched on Mount Olympus, Greece, which was not visited by Ferdinand, but on Mount Olympus (Ulu Dağ), Turkey (p. 64). There are also minor discrepancies: whereas the dates of origin of two Byzantine manuscripts, the Codex Vindobonensis (Vienna, Österreichische Nationalbibliothek) and the Codex Neapolitanus (Naples, Biblioteca Nazionale di Napoli), are given correctly on p. 15, they are mixed up on p. 27; the date of Franz Bauer's death is correctly given as December 1840 on p. 151, but not on pp. 71 and 226. The present reviewer was able to spot a single omission – in Chapter 9 “Stability at last”, dealing with Ferdinand's final years, no mention is made of the continued production of water colours in Vienna representing animals documented during the Investigator voyage, although archival evidence for this fact exists (Lack 2015).

But all these are minor points compared to the wealth of complex and detailed historical as well as biological information correctly presented. An example may illustrate this point: in the legend accompanying Ferdinand's colour-coded pencil drawing of Pseudocheirus peregrinus, we learn that this possum re-ingests “soft” faeces “allowing them [it] to thrive on low-energy Eucalyptus leaves” (p. 103). Small is the number of speculative statements, e.g. “Ferdinand Bauer's technique therefore has his origins in his father's opulent flower pieces and game paintings” (p. 18) or “the influence of his father's style is apparent …” (p. 226) because not a single work of Ferdinand's father is known to exist today.

For obvious reasons special care has been attached to the selection of the illustrations, of which several have never been published before, e.g. Aylmer Bourke Lambert's portrait (p. 61) kept in the National Portrait Gallery in London; Ferdinand's “lost” monochrome drawing of Prumnopitys taxifolia (p. 71), now in a private collection in Australia; or a partly coloured pencil drawing, perhaps by the Zehner brothers, who had apparently tried to crack Ferdinand's colour code, kept in the Naturhistorisches Museum in Vienna. However, the bulk of the previously unpublished illustrations are Ferdinand's colour-coded pencil drawings from the Investigator voyage. Four illustrations (pp. 214, 217, 218, 221) have been included in the last chapter with the note “attributed to Ferdinand Bauer”, although there are facts to the contrary (cf. Lack 2003).

There is an appendix listing all animal and plant names dedicated to Ferdinand together with the names currently regarded as correct (pp. 228–230), notes (pp. 231–235), a bibliography (pp. 236–238) and acknowledgements (pp. 239–240). The volume ends with a pleasingly comprehensive index listing the names of persons, animals, plants, localities and general terms (pp. 241–246).

The layout is of excellent quality, in particular the arrangement of illustrations, which often enable the reader to compare at a glance the colour-coded pencil drawing (for Flinders's Voyage, all in the Naturhistorisches Museum in Vienna) with the finished watercolour (for Flinders's Voyage, all in the Natural History Museum in London), sometimes additionally also with the engraving based on them. Careful attention has been given also to all aspects of the production of the book, i.e. to paper quality, colour fidelity in the printing process and solid binding.

In short, this is an exquisite book in full agreement with the motto preceding David's introduction “The greatest enterprise of the mind has always been and always will be the attempted linkage of the sciences and the humanities”. Ferdinand would have been satisfied.