World Library  
Flag as Inappropriate
Email this Article

One-Million-Liter Test Sphere

One-Million-Liter Test Sphere
Nearest city Frederick, Maryland
Built 1951
Architect Unknown
Governing body United States Army
NRHP Reference # 77000696 [1]
Added to NRHP November 23, 1977

The One-Million-Liter Test Sphere — also known as the Test Sphere, the Horton Test Sphere, the Cloud Study Chamber, Building 527, and the “Eight Ball” (or “8-ball”) — is a decommissioned biological warfare (BW) chamber and testing facility located on Fort Detrick, Maryland, USA.[2] It was constructed and utilized by the U.S. Army Biological Warfare Laboratories as part of its BW research program from 1951 to 1969. It is the largest aerobiology chamber ever constructed and was placed on the National Register of Historic Places in 1977.


  • The structure 1
  • History 2
  • See also 3
  • References 4
  • External links 5

The structure

The stainless steel test sphere, a cloud chamber used to study static microbial aerosols, is a four-story high, 131-ton structure. Its 1-inch-thick (25 mm), carbon steel hull was designed to withstand the internal detonation of "hot" biological bombs without risk to outsiders. It was originally contained within a cubical brick building.

Its purpose was the study of infectious agent aerosols and testing of pathogen-filled munitions. The device was designed to allow exposure of animals and humans to carefully controlled numbers of organisms by an aerosol (inhalational) route. Live, tethered animals were inserted into the chamber along with BW bombs for exposure tests. Human volunteers breathed metered aerosols of Q fever or tularemia organisms through ports along the perimeter of the sphere.


The bottom of the sphere, in use

Herbert G. Tanner, the head of Camp (now Fort) Detrick's Munitions Division, had envisioned an enclosed environment where biological tests could be conducted on site, rather than at remote places like Dugway Proving Ground, Utah and Horn Island, Mississippi.

The facility was constructed during 1947 and 1948 and became operational at Camp Detrick in 1950 .

The test sphere was utilized during the Operation Whitecoat studies (1954–73), the first exposure taking place on January 25, 1955.

The test sphere has not been used since 1969, when the US offensive BW program was disestablished by President Nixon. The brick building housing the test sphere was destroyed by fire in 1974. However, the chamber itself was placed on the National Register of Historic Places [1] in 1977.

See also


  1. ^ "National Register Information System". National Register of Historic Places.  
  2. ^ Guillemin, Jeanne (2005), Biological Weapons: From the Invention of State-sponsored Programs to Contemporary Bioterrorism, Columbia University Press, pg 97.

External links

  • Photos of the “Eight Ball” [2][3][4]
  • Ethical and Legal Dilemmas in Biodefense Research
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.