December 23, 1791: James Peacock, a London architect of note in his day, was granted the first British patent on a process and apparatus for water filtration (December 23, 1791, No. 1,841). In 1793. Peacock published a promotion pamphlet setting forth the need for filtration and the principles that should guide the choice, preparation and placing of filtering media, showing sketches of filters of different sizes and design. It includes a diagram showing superimposed spheres of diminishing size, illustrating a mathematical exposition of the reasons why coarse filtering material should be placed at the bottom of a filter with layers of material of regularly decreasing size above it. Peacock’s exposition brings to mind the Wheeler filter bottom designed more than a century afterwards. No such thesis had appeared before Peacock’s day and none surpassing it has appeared since….
Peacock’s Design.-The novelty of Peacock’s invention, he declared in his patent, was filtration by ascent instead of the common method of descent. This could be applied under any head, in any quantity and for public as well as private use. A further novelty, far more significant, was cleaning the filter by reverse flow, the descending water carrying with it “all foul and extraneous substances.”
Reference: Baker, Moses N. 1981. The Quest for Pure Water: the History of Water Purification from the Earliest Records to the Twentieth Century. 2nd Edition. Vol. 1. Denver, Co.: American Water Works Association, 67-72.
Commentary: Even though Peacock’s filter was a failure, it marked the beginning of period of experimentation which resulted in the successful slow sand filters that are still used today.