Picture Special: Nineteenth century Ireland has been revealed in a series of photochrom postcards
The spectacular images show still familiar sites and locations
These images were produced using the photochrom method allowing colourised photographs from black and white negatives via the direct photographic transfer of a negative onto lithographic printing plates.
It was invented in the 1880s and was most popular in the 1890s, when these images were taken. Although true colour photography had been developed by then it was not commercially practical yet..