The first reference to workings at Kelly dates from 1797, when the landowner, George Wills, leased to John Pinsent for 21 years a 'certain mine of black lead or some other substance'.  The black lead was actually micaceous haematite, ferric oxide Fe₂O₃.

 

The first official record of the mine is in 1877 when it was leased to the Kelly Iron Company with Captain W. H. Hosking in charge.  For the next 13 years only two or three men were employed, production averaging some 25 tons per year.  In 1892 the mine was advertised for let by J. Dadd of Kelly and was stated to "contain several valuable lodes and to be equipped with a waterwheel and stamps for ore-dressing.  A  better supply of water for processing the ore and working the water wheel than that from the small Kelly stream was needed, and probably in the 1870s a source was set up at the Bullaton stream, most likely with a launder running for about a quarter of a mile around the hillside to feed a holding pond above the mill.  

 

Up to 1900 the mine appears to have remained idle, until the Scottish Silvoid Company of Glasgow took over the lease with Mr. A.W. Govan as manager and Mr. Samuel Hill as mine captain.  In 1901 thirteen men were working at Kelly, perhaps mainly doing development work as production in that year was only 20 tons.  From then on output steadily increased, reaching a peak of 202 tons in 1907 in which year the photograph was taken of the Kelly miners standing in front of the shaft.

 

In 1913, nine men were recorded as working, four underground and five on the surface.  The Ferrubron Manufacturing Company, then working the much larger Great Rock Mine at Hennock and several other mines in the area, took over around 1917.

 

In 1915 the first turbine was installed to replace the stamps waterwheel, to be replaced in turn by the current Turgo impulse turbine in 1920.  Also during the 1920s, compressed air rock drills were tried, but due to the soft nature of the ore, water dust suppression was not used for fear of washing the valuable material away.  As a result, the miners started to suffer from silicosis.  A Blackstone oil engine was installed in 1934, to supplement the water power during the dry summer months.  Improvements to the water supply included those to the dam at the Bullaton stream take off point and laying a stoneware pipe to the turbine pond above the mill.  Over the 60 or so years after closure the dam wall was badly damaged by falling trees and the pond became silted up.  In 2014 KMPS members completed a major project to clear the pond and rebuild the dam wall, so the water supply from 'quarter mile pond' can again work the water wheels and turbine, and support ore processing.  

 

Around 1947 the ore-processing plant was brought back into use by the company then operating the Pepperdon Mine some way up the valley near Moretonhampstead.  New underground workings were opened to the south-west of Kelly on the westward extension of the old Hawkmoor Mine lodes, and this working became known as Slade Mine.  The ore was trucked to Kelly for processing through the Californian stamps before being taken by lorry to the modern finishing and drying plant at Pepperdon.  In 1951 blasting broke into unrecorded 'old men's workings' followed by a major underground collapse, fortunately at night, which brought mining to an end.  The company never recovered from these setbacks and both Kelly and Pepperdon Mines were abandoned.

 

The reconstructed water wheel at the side of the mill. The original wheel drove a set of Cornish stamps, and the present wheel runs a roughly 1/3 scale working model, showing the difference between the Cornish and Californian types.  During the restoration of the mill used Cornish stamp heads of at least two sizes were found, so it is possible that the stamps were changed or modified during the 19th or early 20th century.

When a mine finally closed it was usual to sell off the equipment, either for its scrap value or for use at another mine. However, due to a legal dispute over payments to the land owner, the site at Kelly was left untouched for many years. This resulted in what is now a unique collection of mining machinery on its original site.