hounslow mill

“Hounslow, whose heath sublimer terror fills,
Shall with her gibbets lend her powder mills.”

WILLIAM MASON “Heroic Epistle” 1773

There were two things that must have depressed people living around these parts in the 18th and 19th centuries. The first was the likelihood of being robbed by highwaymen and footpads on Hounslow Heath. The second was the real possibility of being blown up by any one of the many gunpowder mills operating along the River Crane.

Although it is difficult to prove, it does seem that this area has had a long association with explosives…

“… It is said that the first gunpowder manufactured in England was probably here; we are told that one William of Staines was employed by Edward III in 1346 to make the gunpowder which enabled him to gain the victory of Crecy, the first battle in which gunpowder was used.”

EDWARD WALFORD Writer and Historian 1823-1897

safety sign

The Hounslow gunpowder mills may have been at the scientific and technological cutting edge and vital to the nation’s defence; they may have used the most sophisticated safety procedures, one of which involved dampening the powder with the urine of wine-drinking bishops – but it didn’t stop them blowing up with monotonous regularity…

March 1758 – ‘The powder mills at Hounslow blew up today, but happily no lives were lost.’ (This huge explosion was felt in Reading, 26 miles away.)
December 1758 – ‘At night at about twelve o’clock a store of gunpowder at Hounslow took fire and blew up. Several windows 300 yards from the works were shattered. What might be the cause is unknown, but in many places it was supposed to be an earthquake.’

The explosions of 1758 were nothing when compared with a major detonation in September 1770 -

destroyed gunpowder mill

‘Yesterday morning exactly at half-past nine eight powder mills blew up at Hounslow Heath by the explosion being communicated from one to the other; the shock was so great that there was scarce a pane of glass left whole in the parishes of Twickenham, Brentford, Teddington etc, most parts of London and Westminster likewise felt the shock and imagined it an earthquake….the inhabitants of Brentford, Hounslow, Twickenham and Isleworth etc have advertised for a meeting to petition Parliament for the removal of the powder mills, as not only the inhabitants, but travellers, (they being so near the high road), are now in eminent danger thereof.’

One woman living in Stockwell, 10 miles away from the explosion, was so disturbed by the unnatural and violent shaking of her house that she was convinced that her maid was “having intercourse with a wicked spirit”. When she threw the maid out the shaking ceased. Q.E.D!

Another person rattled by the bang was local dignitary and man of letters Horace Walpole who lived at Strawberry Hill. When he came home that evening he discovered eight of his stained glass windows broken…

“My shattered castle never did look so Gothic in all its born days. You would swear that it had been besieged by the Presbyterians in the Civil Wars, and that finding it impregnable they had vented their holy malice on the painted glass.”

There were other explosions. On Sunday April 1774 the congregation in Isleworth Church fled into the churchyard thinking that the entire building was about to collapse around their ears. On September 25th 1774, after another explosion, a man’s head was found more than a quarter of a mile from his body.

The worst detonation of them all was recorded on in January 1776…

shot tower

“Between eight and nine o’clock this day the powder mills at Hounslow, owing to the wheels not being properly supplied with oil, took fire and blew up with a dreadful explosion, which not only terrified the inhabitants of the place, but alarmed the City of London. Three men at the works were killed and the flames reached a boat in the mill river, in which were thirty barrels of gunpowder, set fire to the whole and blew it up with a terrible explosion; the man in charge being shattered to bits and the boat blown clean out of the water. Not a vestige of the mills is left standing and Hounslow Heath is covered with bricks and tiles, and the mangled remains of the unfortunate sufferers. The houses in Hounslow, Isleworth and Brentford have suffered considerably, without a whole pane of glass in their windows and the inhabitants so terrified that they not only forsook their dwellings, but a number of women and children, through fear, appeared half naked in the streets, expecting every moment that the houses would fall and bury them. The scattered limbs of the victims were, by order of the magistrates, collected and deposited in the Churchyard. The loss of the valuable manufactory is estimated at near £20,000.”

The explosions continued throughout the 19th century. One in August 1813 was so powerful the shock wave set the church bells ringing in Brompton Church on Knightsbridge, 8 miles distant. The last explosion, a double blast, was in 1906 by which time local gunpowder milling was coming to an end. The last mill closed in 1927. The only symbol now remaining of what was once an important industry is the Shot Tower in Crane Park where they made musket balls and shot.

gunpowder explosion

A Story Following the Double Explosion of 1906

In Stanwell village, 5 miles from the blast, was an old man, long stone deaf, who was working in his garden at the time of the explosion, and when the double “Boom” rang out he stood up with a pleased smile and remarked to his grandson, “Bless my soul! Why, that’s the first time I’ve heard the cuckoo in thirty years!”

There is an article about the Crane Park Shot Tower published on 19th November 2009.

— from Martyn Day

Credit: Much of the information in this article came from “Highwayman’s Heath” by Gordon S. Maxwell, published in 1935