The Shot Tower, built in 1828 (amazing it's still standing really)
Friend John Royle and I went on a bike trail through the Crane Park in Twickenham this morning, to visit the tower there. We were partly on a mission too, intent on assessing the merits of a relatively recently floated theory it may actually have been a windmill used for recirculating water to power the gunpowder mills, rather than a shot tower for the swift manufacture of large quantities of consistently sized and round lead balls / shot. They were probably for use with muskets, but ball size may have varied depending on the bore of the weapon. Typical diameters in the UK were approximately as follows, with the musket ball at about 1.14 oz being the heaviest":
Musket 0.68”
Carbine 0.60”
Pistol 0.51”
7 Barrel Gun 0.46”
The French favoured a musket ball of 0.69” in diameter, while the Germans went up to 0.78”.
I realise by getting into some detail above I’m already rather giving our conclusion away, but from here on in I’m going to refer to the tower as The Shot Tower.
Hounslow gunpowder mills were sited along the banks of the Crane River on the west side of the thirty hectare Crane Park, between Twickenham and Whitton. Marking the site today is the only surviving whole building, namely the twenty-five metre high Shot Tower.
The mills were apparently established during the reign of Henry VIII, or possibly earlier. (I'd be surprised if Henry had anything to do with it, what with all of that eating and beheading). The location was chosen for various reasons, including the ready availability of Willow and Alder wood from the river banks for making charcoal, a constituent of gunpowder; water power from the river for the mills; and the river itself for transport / barges. Furthermore the open land, back then relatively distant from settlements, was an added advantage for the location of a fire hazard (well you might have assumed as much, but hold that thought). Gunpowder manufacturing continued there until the last mills were closed in 1927.
It was a dangerous business, and despite workers wearing felt shoes and soles to avoid the risk posed by sparks, over the years there were a number of explosions, and lives lost. And windows broken. In March 1758 an explosion was felt thirty miles west in Reading, and in April 1774 another explosion terrified people at church three miles east in Isleworth. In 1772 three mills exploded, shattering glass and buildings in “the neighbourhood”, which just happened to extend two miles east to Strawberry Hill House where the alarmed and irate owner Horace Walpole wrote complaining to his friend and relative Seymour Conway, then Lieutenant General of the Ordnance, that all of the decorative painted glass had been blown out of his windows.
Of yet another explosion a Joseph Farington noted on Monday, January 25th 1796 in his diary:
"The Powder Mills at Hounslow were blown yesterday. The concussion was so great as to break the windows in the town of Hounslow ... 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, with all of the burials taking place on January 27th 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 July 24th 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 July 31st.
Burial records note deaths from further explosions into the 1800s. Abraham Slade noted in his diary for 1859 that:
"On the 29 of March the Powder Mills blew up, sending 7 poor souls to eternity in a moment. It has broken a great deal of glass in Twickenham & neighbourhood. We thought the whole place was coming down.”
The last major explosion recorded was in the summer of 1915.
As mentioned earlier, recently there have been claims The Shot Tower was a windmill. Indeed, it is officially now adorned with the imaginative name The Brick Tower. John and I came away from this morning’s visit unconvinced, seeing no evidence on or around the tower of remains or scarring in keeping with the windmill theory. Far more likely it was a shot tower. Anyway, it's a bit of a stretch to think a windmill could account for such carnage as that described in this post. I think our considered conclusion is that the windmill theory is a load of balls.
This was the traditional way to make musket balls for your army:
1. Take a lump of lead
2. Heat it in a crucible until it melts
3. Carefully pour the molten lead into a mould
4. Wait until the lead has solidified
5. Break open the mould and remove the lead ball
6. File off any high spots or lumps
7. Check the ball for irregularities by rolling it down a slope
8. Repeat the above 10,000 times - more if you have a large army
This process prevailed until 1782 when a Bristol plumber had a strange dream. William Watts imagined he saw raindrops forming into perfectly round spheres as they fell through the air. Wondering if molten lead would behave in the same way he experimented by pouring molten lead through a sieve from the tower of his local church.
It worked: sieve, lead, heat, height, gravity, water.
Men at work
Encouraged by his success he experimented further, adding a three-story tower to his house and digging a shaft underneath to achieve a longer drop. Later in 1782 Watts patented his process and made a fortune. Soon “Shot Towers” were being constructed all over the world, from Finland to Philadelphia, from Tasmania to Twickenham.
How it works. A Shot Tower is essentially a tall, hollow structure, with a heating chamber at the top. Here lead is heated until molten, then poured through a copper sieve. The size of the shot is determined by the size of the holes in the sieve. As the drops of molten lead fall through the air surface tension forms them into spherical balls. At the bottom of the tower the lead shot is caught in a water-filled basin. It is then removed from the basin and rolled down an inclined table to check it is completely spherical. Any shot that is “out of round” is sent back up the tower to be melted again. The final stage of the process is to polish the shot with a little graphite to prevent oxidation.
Trees and tower
Nice tributes to the NHS during Covid
Photographs courtesy of John Royle, (apart from the lead balls and “Men at work”)
Red arrow: Shot Tower
Blue arrow: Scene of Walpole's hissy fit as he surveyed his damaged painted glass windows, two and a half miles from the source of the explosion
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