Wednesday, January 15, 2014

Gunpowder Mill on Powder Mill Road

Label would have been on a wooden keg or tin can
of black powder. Courtesy Maynard Historical Society
Ka-boom! There was a 105-year history of gunpowder manufacture in this area. A 1921 history of Maynard noted that many local men found employment in the American Powder Mills, adding, "...occasional explosions, sometimes serious, do not permit us to ignore their [APM's] existence." A newspaper account of an explosion on March 12, 1878 described widely scattered body parts of two workers being gathered in pails, including a detached finger with a gold ring. The location of this spread-out complex was along what is now Route 62, encompassing parts of Maynard, Acton, Concord and Sudbury, on north and south sides of the Assabet River.

Millstone in the woods, likely deposited by an explosion.
Ruins of a building, including bent one inch diameter
steel rods and broken timbers, about twenty yards away.
The black powder manufacturing process in brief: potassium nitrate, sulfur and charcoal are each milled separately to a fine powder then mixed together while dampened with water. The blend is pressed to remove water, the resultant slab, called "presscake" then broken into the desired coarseness (for cannon) or fineness (for guns) in the kernel-house, sieved to remove dust, resulting grains glazed with graphite to prevent sticking, dried in a drying oven, and then packed into copper-nailed oak barrels or tin containers. 

Same stone, uncovered; estimated weight 4,000 pounds.
Dimensions are 58 inches across and 16 inches thick.

Thoreau’s journal mentions the gunpowder mills several times. Passing by on an 1851 walk to Lake Boon, Thoreau complained that the harsh chemicals irritated his throat. Later the same year he recounted having asked a worker about the dangers of working with gunpowder. Per his journal, the workmen wore shoes without iron tacks, so as to reduce the risk of striking a spark. The workers considered the kernel-house the most dangerous, the drying-house next, and the press-house next.

Two years after Thoreau's first journal entries there was an explosion at the mill. Thoreau wrote: “About ten minutes before 10 a.m. I heard a very loud sound and felt a violent jar which made the house rock and the loose articles on my table rattle... I jumped into a man’s wagon and rode toward the mills.

"Arrived probably before half past 10:00 a.m. There were perhaps 30 or 40 wagons there. The kernel mill had blown up first and killed three men who were in it said to be turning a roller with a chisel… and fragments mostly but a foot or two in length were strewn over the hills and meadows, as if sown, for 30 rods [165 yards]. Three other buildings were destroyed or damaged.

Courtesy Maynard Historical Society
"Some of the clothes of the men were in the tops of the trees where undoubtedly their bodies had been and left them. The bodies were naked and black. Some limbs and bowels here and there, and a head at a distance from its trunk. The feet were bare, the hair singed to a crisp. I smelt the powder half a mile before I got there."

Henry David Thoreau was rubbernecking at the site of the gunpowder mills that Nathan Pratt built in 1835 and owned until 1864. Because of the dangerous nature of gunpowder, this type of operation was typically composed of modest-sized wooden buildings quite a distance apart. Under subsequent ownerships by the American Powder Company, American Powder Mills and American Cyanamid Company, the operation grew to some 40 buildings scattered over 401 acres, employing at times as many as 70 men and women (the latter to assemble cartridges).

Descriptions of the time mention willow tree trunks being brought in from Sudbury to make the charcoal, and of unshod mules being used to pull wagons within the mill compounds because of the fear that horseshoe shod horses might strike sparks. Coming off work, men would leave their gunpowder-soiled clothing in the changing room and wash thoroughly - including their hair - before changing into clean clothes to go home. 

"DEAD SHOT" watch fob (Internet download)
Click on any photo to enlarge.
American Powder Mills added production of smokeless powder, including the renowned brand "Dead Shot," but continued making black powder. Interestingly, during World War I the facility's entire production was contracted to the Russian government. And why weren't they selling to the U.S.? Because DuPont had an exclusive contact.

The first fatal explosion mentioned in historic records occurred in 1836. The Concord Freeman newspaper reported that three men were blown to bits and a fourth succumbed hours later to burns and fractures. Various records documented 23 explosions - most with fatalities. A New York Times article told of five deaths in a multi-building series of explosions on May 3, 1898. A September 4, 1915 explosion was heard as far away as Lowell and Boston. The last three explosions on record took place in 1940; the mills were closed shortly thereafter.

Soon after gunpowder manufacture ceased ownership of most of the land in Acton devolved to W. R. Grace, an international chemical company, and later still to various business sites such as the Stop & Shop Plaza and the car dealerships on both sides of the river. Remnants of gunpowder mill buildings can be seen on forays into the woods. The dam still exists, with an adjoining, recently modernized hydroelectric facility operating under the name Acton Hydro Company. Electricity is sold to customers of Concord's municipal power company.

Tax records show that in addition to the various mill buildings the facility included boarding houses for workers and also a small gauge railroad. The latter was probably used to bring raw materials in and finished goods out to the regular railroad. The engine could have been a fireless steam locomotive - meaning that it operated off a pressurized tank filled with superheated water at a site distant from the actual gunpower manufacturing buildings. This would eliminate the risk of a trains' smokestack cinders setting off fires and explosions. Oh, and the A.O. Fay shown as President in the label was the son of A.G. Fay, previous owner, who died in an explosion in 1873.    


  1. Another good treatment of the powder mills including pictures of some of what remains of the buildings...

  2. I added millstone photos since posting this. The millstone is a puzzle because it has grooves as if to be a horizontal grain millstone, but also iron bars as if to be vertical, using the edge to crush (typical of a gunpowder mill). My guess is that it was a grain stone, repurposed.

  3. I inherited a framed adv. poster (lge) from my Grandfather upon his death in 1965. It shows 2 men firing from a small boat/dingy with the resulting "Dead Shot" bird l falling logo in the foreground. Oak frame has "Gunpowder' engraved/carved in it. I am very proud to own this piece of history!!

  4. My paternal grandfather died in one of the mill explosions......last name Waterhouse.....early 1900s.........wife and he lived on Powder Mill Road.....she later remarried a Thomas Fox whom I think worked at the mills too......any information, advice, direction to help in my quest would be greatly appreciated....thank you for you time

  5. Records show Thomas Waterhouse died in 1908 from explosion at gunpowder mill. Buried in Glenwood Cemetery, Maynard. Theresa (poss. Thresa) L. Waterhouse Fox (1883-1947) buried with husband Thomas F. Fox (1886-1963) both buried at Glenwood. Find-A-Grave has a photo of the gravestone.