Maria Reiche Grosse-Neumann was born into a middle-class family in the city of Dresden in 1903, and studied mathematics. In 1932 she took the huge step of emigrating to Cuzco, the ancient Inca capital in the south of Peru, to work as the governess for the German consul's children. It was then that she first began to explore the Andes and the high desert plains of the south of the country, which made a lasting impression on her.
In 1934, she moved to the Peruvian capital, "Lima the horrible", where she set herself up as a teacher of German. One of her first clients was an American woman, Amy Meredith, who ran a fashionable coffee shop in the capital. It was there that Maria Reiche met someone who changed her life completely, as she discovered the cause to which she was to dedicate her next 60 years.
In the late 1920s, the Peruvian archaeologist Toribio Maj'ia Xesspe had discovered traces of long straight lines drawn in the plains of the desert around Nazca, some 400km south of the capital. The great puzzle was as to what they might represent, a mystery that only increased when the American geographer Paul Kosok flew over them in an aeroplane and took photographs that showed from the air that many of them were in the shape of birds and animals, or geometric shapes. Who had made them, and why?
When Reiche heard from Kosok of these mysterious shapes in the desert, she knew immediately she wanted to devote herself to their study. She transferred to Nazca and set about discovering, measuring, and cleaning the lines. She described the site, which covers more than 365 square kilometres, as "a huge blackboard where giant hands have drawn clear and precise geometric designs".
She herself was regarded as almost as strange as the lines themselves. "I used to live on a flat roof or sleep out in a tent in the desert," she recalled in later life. "The locals either thought I was a spy or completely mad. Once a drunk threatened me with a stone, so I took out my sextant and pointed it at him. He ran off screaming, and the next day the local papers ran the story of a mad and armed German spy in their midst."
Gradually Reiche managed to convince the locals and many others that she was a serious scientist who had uncovered something of great importance. She and Kosok became convinced that the "Nazca lines" were an astronomical calendar representing the constellations of the southern hemisphere.
For example, Reiche interpreted the huge monkey shape she found as being an image of the Great Bear, whose movements through the heavens were important to the ancient inhabitants of Nazca for measuring time and the onset of the rainy season. In the late 1940s, Reiche published her theories on the Nazca lines in The Mystery of the Pampas, which attracted widespread attention to the phenomenon.
The fact that these lines only seemed to make sense from the air soon led to many fanciful conjectures, including the one popularised by Eric von Daniken that they must have been some kind of sign to extra-terrestrials. Reiche always rejected this idea, seeing it as an insult to the engineering capacities of the ancient inhabitants of Peru. Her own interpretation of the lines as an astronomical chart has however also been superseded, as they are now more frequently seen as having a ceremonial and community strengthening functions.
There can be no doubt though that Reiche's almost single-handed devotion to the study of the lines was of vital importance in saving them against the encroaching demands of man. Until late in life, she was a familiar figure in the southern plains, rushing out with her broom to sweep the lines clean, or trying to keep lorries, cars and tourists off them, or up her stepladder making yet more mathematical calculations to prove the lines were a copy of the heavens.
For the last 25 years of her life, Reiche took up residence in room 130 of the tourist hotel in Nazca, which by the 1970s had become the second most important tourist destination in Peru. Her sister Renata came to look after her as she became increasingly frail. At the age of 90, in 1993, Reiche published Contributions to Geometry and Astronomy in Ancient Peru which gathered together all her articles and scientific publications on the Nazca lines from over 40 years.
Although her theories fell out of fashion, Peruvians felt immense gratitude and affection towards the woman known as "the lady of the lines". In 1992 she was awarded Peruvian citizenship, one of her greatest wishes. The Nazca lines were declared part of the patrimony of humanity by the Unesco in 1994, and earlier this year the same organisation recognised Maria Reiche's importance by awarding her a special silver medal for her lifetime's work.
Maria Reiche Grosse-Neumann, mathematician: born Dresden, Germany 15 May 1903; died Lima, Peru 8 June 1998.