If you are startled to see a vivid blue photograph on Timebinder, it is a cyanotype, one of the least pleasing or successful of the early print processes – not my cup of tea either.
Sir John Herschel discovered the formula in 1842: equal parts of Potassium ferricyanide and Ferric ammonium citrate are dissolved in water, the paper is saturated in it and dried in the dark; when exposed in sunlight (or any ultraviolet source) through a photographic negative (or plants, flowers or anything that light will penetrate) the Prussian blue dye is evident when the paper is washed with water. Because it is a chemical salt that is "in" the paper itself instead of silver or platinum salts that are in an emulsion "on" paper, the results are rather coarse and incapable of revealing the tonal range of the black and white images we are accustomed to seeing. Below is the same image converted to grayscale which is easier to look at (perhaps because we are accustomed to it), but it still does not have much dynamic range.
Having dispensed with the process, we can deal with the image itself. I do not know where it was taken or who manufactured it, but it is an early self-propelled 20th century model that is the heir to the horse drawn steam pumpers used as early as 1829 in England and well into the 1900s. Why did it take so many decades to decide to use the power from the steam to drive the vehicle as well as the pumps, after all, the invention of steam engines had always been for pushing, pulling, pumping, sawing and motive power? The self-propelled fire engine steamer wasn't around very long because the internal combustion engine was soon capable of greater power, was easier to maintain and inherently safer to operate (any steam engine in the wrong hands was patently lethal; it's dangerous enough fighting fires without worrying about being blown up!) The Stanley Steamer automobile couldn't compete with the gasoline engine either.
