The Gunpowder Mills
An early industry
c1540 - 1927
Known as the Hounslow Gunpowder Mills this manufacturing enterprise was actually sited between Twickenham and Whitton along the banks of the Crane River. It is known that gunpowder was invented during the first half of the 14th century and probable that mills were established on Hounslow Heath during the reign of Henry VIII, if not before. One of the constituents, charcoal, was produced from Willow and Alder, readily available from the river banks. The river also offered water power for the mills and transport for barges. The open land, relatively distant from settlements, was an added advantage. Manufacture continued until the last mills were closed in 1927. The site is today marked by the only surviving building in Crane Park: the Shot Tower.
The millstones in the foreground were used to grind saltpetre, an ingredient of gunpowder.
A hazardous operation
It was a dangerous business and there were regular explosions and loss of life. On 11 March 1758 one of two explosions was felt in Reading, and in April 1774 another explosion terrified people at church in Isleworth. In 1772 three mills blew up, shattering glass and buildings in the neighbourhood. Horace Walpole wrote complaining to his friend and relative Seymour Conway then Lieutenant General of the Ordnance. All the decorative painted glass had been blown out of his windows at Strawberry Hill.
There were, by this time, a number of mills operating under different ownerships and the growth of the industry had caused concern locally. In 1757 the Earl of Northumberland, as Lord of the Manor, had granted a lease to John and Edmund Smyth for the construction of a mill to grind corn. Gunpowder manufacture was not to be undertaken without consent and in fact this was only granted in 1768. It had almost certainly started earlier, probably with the connivance of the Earl. Part of the permission required a barrel of gunpowder to be delivered to Syon House each year.
Joseph Farington noted in his diary on Monday 25 January 1796 that: "The Powder Mills at Hounslow were blown yesterday. The concussion was so great as to break the windows in the town of Hounslow. Hoppner having been to Eaton, on his return rode to the spot where the Mills had stood, not a fragment of them remained. They were scattered over the country in small pieces. Three men were killed”.
In fact, there were four deaths: William Hollis, Matthew Weeving, Joseph Perry and Richard Winterburn, all buried on 27 January as recorded in the registers for St Mary's Church, Twickenham. The entry adds a note: "These four unfortunate poor men suffered instant death on Sunday ye 24th by the explosion of ye Corning (granulating) House of a Powder Mill in this Parish". There was a further explosion on 24 July that year when Edward Ponter, William and James Joise (sic) "met instant death on ye 24th by ye explosion of a Gunpowder Corning Mill as did their unfortunate brethren in January last". They were buried on 31 July.
Burial records note deaths from further explosions: 5 on 17 November, 1 on 19 June 1798, 7 0n 15 July 1799, 2 on 27 June 1801, and so on through the century. Abraham Slade noted in his diary for 1859 that: On the 29 of March the Powder Mills blew up, sending 7 poor souls into eternity in a moment. It has broken a great deal of glass in Twickenham & neighbourhood. We thought the whole place was coming down.
Only one death is presently known to have been recorded on a gravestone: that for William J Lewcock at St Margaret's, Hanworth.
The last major explosion recorded was in the summer of 1915.
T H R Cashmore, Richard Cobbett's Twickenham - 1866-1872, Borough of Twickenham Local History Society Paper No53, 1984, p27
T H R Cashmore, Twickenham in 1818, the Year of the Enclosure, Borough of Twickenham Local history Society Paper No38, 1977
Jenny West, Gunpowder, Government and War in the mid-Eighteenth Century, Appendix 1, The Royal Historical Society - the Boydell Press
Horace Walpole, Correspondence
Donald Simpson (ed), Twickenham Past, Historical Publications, 1993
G E Bate, And so make a City here, Thomasons Ltd - Hounslow, 1948