Images of Australian wildlife in 200 shades of green

The Austrian natural history painter Ferdinand Bauer had a prodigious memory for colour. All of us can distinguish bottle from lime, but how many of us could parse 200 different shades of green? Bauer could and he was at the height of his powers when he joined Matthew Flinders' mission to chart the Australian coastline and document its flora and fauna in 1802-3. More than a thousand colours glowed on his mental colour chart. Each was assigned a number and he used this code to mark up the scientific drawings he made of plants and animals in the field. The annotated sketches could then be turned into vividly lifelike watercolours at his leisure.

His pencil drawing of a Port Lincoln ringneck parrot is typical. Paper was limited and the scientists aboard Flinders' Investigator were stingy with its use, so the drawing is done on a small piece, not much bigger than a postcard. The bird is shown looking lively on a twig, though it had been delivered to Bauer dead, two days earlier: "a new parroquet shot by Mr Bell" on February 12, 1802, as the boat lay at anchor off the coast of South Australia. A penumbra of numbers surrounds the bird in Bauer's detailed sketch, each one indicating the colour that would bring the parrot to life.

The process of turning this sketch into a finished watercolour was a slow one. Bauer's paintings were completed up to a decade after the sketches were made and it took him a painstaking week to translate the lines and numbers on the sketch into the imperceptible tonal changes of nature embodied in feathers or fur, petals or leaves. In the finished painting of the ringneck parrot, the bird is almost hyperreal - with a glint in its eye, a slightly cocked head, shadows across the top of its back, and detailed claws gripping a eucalypt twig.

Bauer was the "Leonardo of natural history painting", according to the art historian Bernard Smith, and he painted an unparalleled collection of Australian plants and animals on his journey with Flinders. But unless you happen to grow the sturdy Grevillea baueri, one of the plants named for Bauer, you might not have heard his name. That's all set to change with the launch of a new book by David Mabberley and a dedicated website, developed by the DX Lab at the State Library of NSW, both called Painting by Numbers.

Mabberley's biography, handsomely illustrated with many images that haven't been published before, is an exploration of Bauer's art and life. Mabberley, a British-born botanist who was the former executive director of the Royal Botanic Gardens and Domain Trust in Sydney, suggests that the colour coding started when Ferdinand and his brother Franz (later to become Joseph Banks' botanical painter at Kew Gardens) were set to work as boys copying botanical illustrations from plate books in the local Brothers of Mercy monastery. Banned from messing about with paints in the library, they used a code of some 30 numbers to reference colours. The botanical training Bauer received at the monastery built on an artistic sensibility he had picked up from his father, court painter for the Prince of Liechtenstein resulting in a unique blend of art and science. The spontaneity, beauty and precision of his work, coupled with his complex colouration, meant that by the time he set out with Flinders, Bauer was famous enough to command a salary higher than that of his captain.

Bauer made thousands of sketches of Australian plants and animals, and surely expected more fame, and quite a bit more fortune, to follow him back to England. But history intervened. The watercolours he produced for the British Admiralty, now caught up in Napoleon's final convulsions, were not published and the version he laboriously self-published in Vienna was a financial flop. Consequently, his botanical drawings were seen only by the well-connected or super-wealthy and his animal drawings were not published at all until the 1960s.

The Painting by Numbers website and book, both supported by Peter and Sally Crossing's Belalberi Foundation, expose Bauer's work to a wide audience and Mabberley's research skills, knowledge and contacts have enabled Bauer's drawings and watercolours to be brought together for the first time. There is much international goodwill underpinning the project with the drawings held in the Natural History Museum in Vienna, and watercolours drawn from the UK's Natural History Museum London, Linnean Society London, Royal Botanic Gardens Kew and Bodleian Libraries, and locally from the National Gallery of Australia, the Art Gallery of South Australia and the State Library of NSW.

The website has been developed by the DX Lab, the State Library department charged with using technology and innovative design to engage audiences with the collection and data sets of the library. It opens with a digital palette built from Bauer's colours, with each tile numbered in his handwriting. Bauer's code was "cracked" by comparing the real colours of living plants in Western Australia with the numbers Bauer used on his expeditionary sketches. The research revealed that his mental colour chart consisted of a series of 100 each of red, (numbered 1-100), purple to pink (101-200), pink to mauve (201-300), lilac and violet to blue (301-400), a boggling 200 different shades of green (401-600) plus 100 each of yellow (601-700), orange (701-800), brown (801-900) and up to 100 of white, grey and black. He also used seven different symbols to indicate metallic sheens.

Three hundred of Bauer's watercolours can be explored on the Painting by Numbers site, with the mesmerising highlights being the pairings of finished watercolours with re-sized original drawings. A before-and-after interactive tool turns Bauer's technique into a kind of magic: as the slider moves from left to right, the pencil sketch with its cloud of code numbers becomes a vibrant image of nature. It's addictive.

Tear yourself away from this digital wizardry to browse or make a targeted search, perhaps for that beautiful image of the weedy seadragons; or for all of the drawings that use the shade of tealy-turquoise-green Bauer knew as 485; or for Mabberley's prime example of how Bauer liked to slightly improve on nature, the gymea lily, Doryanthes excelsa. In one of the short, story-based videos on the site, Mabberley explains that Bauer seemed unable to resist the impulse to beautify: he was looking to sell these images after all. His gymea lily is perhaps the most egregious example. In real life the flower head is a tangle of flowers in different stages of coming and going so that it looks a bit like a messy nest stuck on a pole. In Bauer's exquisite drawing, however, each looping flower is in a state of perfection.

Despite the occasional impulse to photo-shop nature, Bauer's illustrations are still scientifically significant. What he saw, where, and when it was flowering, offer an ongoing source of information for scientists. As well, many of the specimens taken on the voyage didn't survive - the fish and other sea creatures, for instance, were eaten by the crew - so that Bauer's drawings are all that remain from the voyage; and the finished watercolours of some fish and plants were the basis for formal descriptions of new species, so are the '"ype specimens", consulted by taxonomists.

For a general audience though, it is the beauty of the illustrations that grabs attention. When the great writer Johann Wolfgang von Goethe saw Bauer's work he praised the way "nature is revealed; art concealed" and pronounced it enchanting. It still is.

Painting by Numbers: The life and art of Ferdinand Bauer by David J. Mabberley is published by NewSouth at $70. Visit the website at dxlab.sl.nsw.gov.au/painting-by-numbers. An exhibition of related material, including original natural history artworks from the collection, will run at the State Library of NSW until January 28, 2018.

This story Images of Australian wildlife in 200 shades of green first appeared on The Sydney Morning Herald.