Lead Shot Towers around the World
Walter Minchinton discusses the rise of buildings used for ammunition manufacture.
How would you make lead shot? This was a problem which concerned ammunition makers ever since guns were invented. An obvious method was to employ moulds and by the eighteenth century multiple moulds were in use which could produce up to twenty shot at a time. But this method was laborious and often a ridge would form where the two halves of the mould met, which was difficult to remove especially when the shot was small. You could make it by dicing or rumbling small square cut from sheet lead in a barrel until the corners were knocked off and approximately round shot was produced. This method was used until the early nineteenth century. Or you could pour molten lead through a sieve into a barrel of water but often the shot produced was distorted or egg-shaped. So none of these methods was satisfactory and meantime, with the wars of the eighteenth century, the demand for shot was growing.
The breakthrough came just over two hundred years ago. According to a legend of which there are many versions, William Watts, a Bristol plumber, who carried on his business opposite St Mary Redcliff, watching the rain fall, possibly in a dream, noticed that the raindrops formed perfect spheres as they fell. Why shouldn't molten lead, he mused, form spherically perfect balls if dropped from a height? Perhaps he tried out his theory from the tower of St Mary Redcliff opposite; perhaps he merely applied what had previously been done elsewhere. Whatever the truth of the matter, there is no denying that William Watts, plumber of Bristol, was granted patent number 1347 on March 28th, 1782, to produce lead shot 'solid throughout, perfectly globular in form, and without the dimples, scratches, and imperfections which other shot heretofore manufactured usually have on their surface'.