One-Million-Liter Test Sphere
Also known as Horton Test Sphere; Test Sphere; Cloud Study Chamber; The 8-Bal
About One-Million-Liter Test Sphere
One-Million-Liter Test Sphere was added to the National Register of Historic Places on Nov 23, 1977. It was among the first 7 of Frederick’s 17 listings. The Register lists it for its science, at the national level.
What it isBuilding in Maryland, United States. From Wikidata (CC0). Read about it on Wikipedia ↗
PDFRead the original nominationThe form that put it on the Register, with its history, photos and a map · 41 MB · National Archives↗Finding One-Million-Liter Test Sphere
North of Frederick on Fort Detrick, in Frederick, MD
No other Register listing is within a short walk. The nearest are under Around it.
13 more Register listings within 2 miles
★ National Historic Landmark · D district · B building · S site. Each opens its own page.
Memories of One-Million-Liter Test Sphere
The record says what it is. Neighbors know what it means.
Your answer becomes a post in Town Square.
Questions about One-Million-Liter Test Sphere
Is One-Million-Liter Test Sphere on the National Register of Historic Places?
Yes. It was added on Nov 23, 1977 (Register number 77000696).
Is One-Million-Liter Test Sphere a National Historic Landmark?
No. It is on the National Register; Maryland has 71 National Historic Landmarks. The nearest is Schifferstadt (aka Scheifferstadt), 0.8 miles away.
Can you visit One-Million-Liter Test Sphere?
Our record doesn’t say whether it is open to visitors. Many listed buildings are private, so it may only be seen from the street.
Where can I read the history of One-Million-Liter Test Sphere?
In its National Register nomination, the form that put it on the Register: a 41 MB PDF at the National Archives, linked on this page.
Sources: National Park Service, National Register of Historic Places (05/22/2026) · National Archives catalog record 106777387 · Wikidata. Map tiles © OpenStreetMap contributors.