On June 7th, 500 feet from Auburn Heights mansion, partway up the hill above the public parking area, the view seen in this image was captured. That evening, smoke from the Canadian forest fires reached a peak particulate density in the air in northern Delaware as well as Chester County PA. The experience reminded us of images we had seen of cities in the U.S., including Wilmington, during the height of the industrial revolution. Similar conditions often occurred on a regular basis when cheap coal was consumed in trainload volumes not only for industrial energy but to heat city homes.

Interestingly, Garrett’s snuff business experienced a peak in sales in the latter 1800s because the interiors of water powered mills, and later steam powered mills, often displayed a haze in the air not unlike what we see in the image. The haze within the mills came from milling operations and not forest fires. How did the textile and grist mills of the industrial revolution lead to a rise in the use of smokeless tobacco products such as snuff?


A grist mill passes wheat, corn, oats, or other grains between a circular stationary or bed stone as a rotating or runner stone a short distance above the bed stone rotates about 120 revolutions per minute. The faces of the two stones are cut with grooves and the rotating stone nearly touches the bed stone allowing the grain to be ground using a shearing action resulting in flour and middlings leaving the millstones. Additional machinery in a mill separates the flour from the middlings and then each component was further separated and packaged. Oliver Evans of Newport, DE, in the 1780s, patented (3rd patent issued by the newly formed U.S. Patent Office) a fully automated process which transformed grain dumped into hoppers from wagons at one side of Evan’s mill into grades of flour packed in wooden casks at the other end of Evan’s mill located in Faulkland DE.

The actual millstone grinding of a grain, along with the various separation steps of the finishing process generated a fine dust which found its way out of the machinery and into the air. Mills with multiple grinding stones generated more flour dust which filled the air and collected on flat surfaces. As a water powered mill, and even for later steam powered mills, the power from the water wheel or steam engine required to operate the mill equipment was transmitted by shafts, wooden and iron gearing, and leather belting all of which required bearings wherever a rotating shaft received support (Washburn Mill line shafts pictured in 1978). A bearing assembly that had lost its tallow lubrication in the 1800s heated rapidly. Likewise, iron gearing, if not continuously lubricated with tallow, might create sparks. Both heat and sparks often ignited the flour dust in the air and accumulating on flat surfaces near the bearing to cause a fire and touch off an explosion.

In Minneapolis, MN the Washburn Mill (Mill A in 1978 pictured) on the shores of the Mississippi began processing flour in 1874 using a rotary millstone process not unlike what Oliver Evans invented. The collection of mills soon became the world’s largest milling operation producing 350,000 pounds of flour daily. The mills, capable of producing more than half of the city’s total milled products, were of large size and each contained air heavily laden with milling dusts while the mill was in operation. In 1878, the C mill capable of milling more than 50 boxcars of wheat daily, created a flour dust atmosphere inside the mill that was described as possibly matching the smoke haze around Auburn Heights on June 7, 2023. Heat or a spark ignited the dust laden air of Mill C and the subsequent explosion resulted in the loss of 18 lives. The explosion leveled the 6-feet thick mill walls to loose stones thrown about a large area and brought down adjacent buildings for more than a city block. Structures within a mile of the mill received cracked walls some of which crumbled to the ground within hours, displaced roofs, and shattered windows.

William Lea, grandson of Wilmington miller Thomas Lea (who owned Auburn Factory from 1813 until 1826 which eventually became Marshall Brothers Paper Mill), experienced a devastating fire at their grist mill on Brandywine Creek (see article at end) in 1894. In 1874 Taylor’s Woolen Mill in Stanton was destroyed by a dust fire putting 100 people out of work. The Dean Woolen Mill in Newark in 1887 was also destroyed by a wool dust fire. Even one of the Garrett Snuff Mills was consumed by fire in 1878 due to tobacco dust catching fire (see article on the rebuild nearing completion). When the Marshall brothers bought Clark’s Auburn Factory in 1890, it had been gutted a few years earlier by a woolen dust fire. In the 1800s countless mills were destroyed and lives lost before mill owners fully understood the many ways airborne plant and mineral dusts could become explosive under the proper conditions.

Dusts of any material are combustible if a sufficient ignition source is introduced. Bearings in old mills could become overheated and ignite layers of accumulated dust laying near them. Any spark in flour dust laden air within a mill might cause an early water powered mill fire and explosion. It was quickly realized that the need to light smoking materials in a dust-laden mill could also become an ignition source and thus smoking was not permitted inside a mill regardless of what product was being produced. As a result, the burning of tobacco products was forbidden within mills. The result created a demand for smokeless tobacco products such as snuff and chewing tobaccos. In order to satisfy a nicotine craving, people turned heavily to snuff. A pinch of snuff placed on the “anatomical or human snuff box” of the hand (red circle in the hand image) and then inhaled in to the nose provided the nicotine directly to the sinus cavity for absorption into the bloodstream.

As a result of the loss of life and the damage to the city, the mill’s owner, Cadwallader C. Washburn rebuilt the Minneapolis mills and in 1879 introduced the nation’s first automatic, all-roller, gradual reduction, flour milling process. More efficient, the process used large polished steel rolls to crush grain instead of rotary grinding to shear the grain, and the addition of dust separators throughout the process nearly eliminated the dust explosion problem which providing ‘gold medal winning’ flours at lower production costs. Eventually the Washburn milling complex became the home of General Mills in 1928. The process was so clean and efficient that the Sharpless family retrofitted their Ashland Mill with roller technology in the early 1880s as did the Lea family on the Brandywine.