The mill buildings used in the manufacture of gunpowder were built with strong stone-walled structures on three sides; but were only covered by light wood structures on the fourth side, which faced out onto the Brandywine Creek.
 When an accident occurred, the explosion was directed away from the other mills and storage areas and over the creek.

Water power was provided from a mill race behind the mills, thus further isolating the mills in case of accident.
One water wheel was often used to provide power to two mills.
Water turbines were introduced in the 1840s.

Alfred Victor du Pont acquired additional property, down stream from the Eleutherian Mills, to add to the manufacturing site.
One of these properties was called Hagley, and it became known as the Hagley Yard.

Most of the industrial remains are located in the Hagley Yard.
The mills were used in the purification, crushing, and mixing of charcoal, sulfur, and saltpeter.
Other mills in the complex were used for glazing and corning, making metal powder kegs, and in cotton and woolen manufacturing.
Stables, offices, a machine shop, and a steam powerhouse from the late 19th century also were located in the complex, as was a narrow gauge railway.
The mill buildings used in the manufacture of gunpowder were built with strong stone-walled structures on three sides; but were only covered by light wood structures on the fourth side, which faced out onto the Brandywine Creek.  When an accident occurred, the explosion was directed away from the other mills and storage areas and over the creek.
Water power was provided from a mill race behind the mills, thus further isolating the mills in case of accident. One water wheel was often used to provide power to two mills. Water turbines were introduced in the 1840s.
Alfred Victor du Pont acquired additional property, down stream from the Eleutherian Mills, to add to the manufacturing site. One of these properties was called Hagley, and it became known as the Hagley Yard.
Most of the industrial remains are located in the Hagley Yard. The mills were used in the purification, crushing, and mixing of charcoal, sulfur, and saltpeter. Other mills in the complex were used for glazing and corning, making metal powder kegs, and in cotton and woolen manufacturing. Stables, offices, a machine shop, and a steam powerhouse from the late 19th century also were located in the complex, as was a narrow gauge railway.
Eleutherian Mills