Mysterious girl? – Even though it's fair to assume that Christina is the photographer's daughter, some uncertainty remains. "We do not know who Christina is," Colin Harding, Curator of Photographs and Photographic Technology at the National Media Museum, said.
"There is no record of Lt Mervyn O'Gorman and his wife, Florence, having any children as far as I have been able to find. There is a census record of a woman named Christina O'Gorman living in Dublin, who was born in the 1890s.
"This would make her about the same age as the model in these photos, and we do know Mervyn O'Gorman had family links in Ireland. It is possible it may be the same person and she's a relative, but we can't say for sure."
A red beach dress – The Autochrome process -- which captured the color red particularly well -- involved a glass plane coated with dyed potato starch, which acted as a color filter.
Subsequent versions, that did away with the glass and used film, remained in use until the mid-1950s, but were eventually overshadowed by more advanced techniques.
An engineer with many talents – "Interestingly, O'Gorman was not a professional photographer, or a member of a photographic society," Harding said.
"He was an enthusiastic amateur who was a professional engineer interested in technology, motorcars and aircraft. His interest in Autochrome photography could stem from his passion for modern innovations, but he did also publish a book on poetry and had other artistic pursuits later in life."
Family portrait – Christina is seen here with her mother, Florence, and her younger sister. Mervyn O'Gorman's camera case lies to their left. Autochrome glass plates did not require any special equipment, and could be used with any camera.
Mervyn died in 1958. His wife much earlier, in 1931. As for the daughters, no records are available.