Philadelphia in Philadelphia County, Pennsylvania — The American Northeast (Mid-Atlantic)
Report from the Fort
17 August 1867 • Lieutenant Colonel C. S. Stewart
New Magazine – is now essentially completed and ready for use. During the year one third of the inner and main arches have been turned; the south wall built; the ventilator flues carried up to the proper height; temporary covers attached thereto; floor timbers and flooring put down and doors hung – 113 cubic yards of concrete backing put in position; roof surface covered with 210 square yards of asphaltic mastic: 900 yards of rammed earthen bankment completed and 822 square yards of sodding placed thereon .
National Archives Philadelphia
The construction of this magazine was proposed in 1864 to hold 1000 barrels of powder (100 rounds for each gun) and to replace a deteriorating structure from 1809. A depression in the ground near the Officers’ Quarters has remained since 1872 when the old magazine was torn down. The new magazine was designed with two concentric brick and concrete barrel vaults separated by an air space to ensure security and insulation from moisture. The air space between the two walls is visible
All the powder magazines at the fort were intended to store powder in casks or barrels for both priming and firing cannon. Cannon were tested or proved periodically even in times of peace. A report from 1869 describes testing the five 15” Rodman guns, two in the water battery (demilune) and three from the ramparts of the fort. For gun number 37 in the water battery, the report states that it was tested “On the 4th of July 1865 – blowing away part of the breast height wall from too great a traverse given the gun.”
Erected by Fort Mifflin Historic Site.
Location. 39° 52.531′ N, 75° 12.809′ W. Marker is in Philadelphia, Pennsylvania, in Philadelphia County. Marker can be reached from W Fort Mifflin Road, on the right when traveling east. Marker is along the walking tour of Fort Mifflin. Touch for map. Marker is in this post office area: Philadelphia PA 19153, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Officers’ Quarters (within shouting distance of this marker); West Sallyport Blacksmith Shop (within shouting distance of this marker); Citadel - 1796 (within shouting distance of this marker); Soldiers’ Barracks (within shouting distance of this marker); Artillery Shed (within shouting distance of this marker); Arsenal (within shouting distance of this marker); Torpedo Casemate (within shouting distance of this marker). Touch for a list and map of all markers in Philadelphia.
More about this marker. The right of the marker contains illustrations of “A Revolutionary War powder barrel known as a budge barrel because sheepskin (budge) sealed the top,” a “Cross section of the 1867 Powder Magazine showing brick and concrete construction and ventilator flues,” and a “Report of Gun Testing at Fort Mifflin submitted by C. Seaforth Stewart, Lieutenant Colonel of Engineers, Philadelphia, December 14, 1869.” Courtesy of the National Archives, Philadelphia.”
Related markers. Click here for a list of markers that are related to this marker. This series of markers follow the walking tour of Fort Mifflin.
Also see . . .
1. The Fort that saved America. The Official Website of Fort Mifflin on the Delaware. (Submitted on October 17, 2008, by Bill Coughlin of North Arlington, New Jersey.)
2. Fort Mifflin Groundplan. Layout of Fort Mifflin, the Fort that saved America. (Submitted on October 17, 2008, by Bill Coughlin of North Arlington, New Jersey.)
Categories. • Forts, Castles • Notable Buildings •
More. Search the internet for Powder Magazine.
Credits. This page was last revised on June 16, 2016. This page originally submitted on October 17, 2008, by Bill Coughlin of North Arlington, New Jersey. This page has been viewed 928 times since then and 3 times this year. Photos: 1, 2, 3, 4. submitted on October 17, 2008, by Bill Coughlin of North Arlington, New Jersey.