Fire Hydrant ‘Sluice Valve’ type.

See ‘Firemen and their Exploits’ by F. M. Holmes published 1899 and available to view online at Project Gutenberg, which states that (referring to London) ‘In addition to 24,284 hydrants of the London County Council, the corporation of the City have 800 hydrants, which are used for watering the streets as well as for extinguishing fires. In the year 1897, no fewer than 466 fires were put out by hydrants and stand-pipes. The increase of hydrants has been very conspicuous under the County Council. Thus, in March, 1889, the number was but 8,881, showing that no fewer than 15,403 were added during the first eight years of the Council's existence. No doubt, still more will follow. On March 31st, 1898, hydrants had been fixed or ordered in 97½ square miles of the county area, leaving a comparatively small space unprovided with these appliances. This space will doubtless be shortly supplied, and it is not unreasonable to suppose that, with the 800 in the City, the metropolis will ere long be sown with a total of about 30,000 hydrants, which, as the twentieth century dawns, may be regarded as among the most effectual means of fighting the fire at the disposal of the brigade. The establishment of these excellent appliances dates from 1871, and is bound up with the system of constant water supply. By the Metropolis Water Act of that year, it was provided that a water company, after giving a constant supply, must notify the fact to the local authority—now the County Council—which must then specify the fire-plugs or hydrants required, and the Council has the power under the Act of requiring water companies to provide a constant supply within parts of their districts. Hydrants are fully charged from the main, and have a commanding cock or tap attached, so that a supply of water can be obtained at once.  The use of these appliances is very important. Planted at convenient and commanding spots, often at the corners of streets or roadways, and at varying distances apart, ranging from fifty to about four hundred feet, according to the circumstances of the locality, and marked also, not only by the plate in the pavement, but by the letter H, placed in a conspicuous position nearby, the fireman can now, at almost a moment's notice, find the hydrant, and obtain an ample supply of water for his engine, or even a jet of water for the fire, before an engine is on the spot. Very different from the troublesome and hindering work of floundering about, possibly in fog or rain or snow, to find the fire-plug, and then to find the turncock which governed the plug. On snowy or foggy nights, the difficulty and delay were sometimes very great; and the substitution of an extensive system of hydrants, with their quickly-obtained water-jets for the old fire-plugs, may rank as one of the most efficient means of fire extinction in the closing years of the nineteenth century.’