Friday Find: What’s in the box? Answered!

NOAA has a box labeled “BALLOON TYPE ML-131-A” from June 23, 1944. Our inaugural “Friday Finds” mission is to figure out what it is and how it was used.

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Calling all students of history! The NOAA Heritage Program needs your help. Email us at heritage.program@noaa.gov if you know how this was used!
Photo of a small box labeled, “BALLOON TYPE ML-131-A”, COLOR: PURE GUM, QUANTITY: ONE, CONTRACT No.: W-33-042-SC-254, WEIGHT: 350 GRAM, ORDER No.: 289-DAY-44, DATE MADE: JUN 23 1944 (stamped on), Molded Latex Products, Inc., PASSAIC, NEW JERSEY"

Photo of a small box labeled, “BALLOON TYPE ML-131-A”. (Image credit: NOAA Heritage)

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Black and white photo of a woman launching a weather balloon.

Update

NOAA’s curator has learned some interesting facts about our balloon in a box. It is a 350 gram radiosonde balloon used for weather observations. Surplus military equipment such as these balloons were transferred to the Weather Bureau after WWII. The Army designation ML-131 indicates a natural rubber balloon, but ML-131-A is made of neoprene. Natural rubber was more durable, but most tropical sources of natural rubber were captured and controlled by the Japanese during WWII, leading the United States to experiment with rubber substitutes like neoprene. Here's how it was described in a WWII Army Field Manual:

This excerpt from April 24, 1944 “TM 11-2405 War Department Technical Manual: Meteorological Balloons” reads “THREE-HUNDRED AND FIFTY-GRAM BALLOON. (1) Radiosonde, Balloons ML-131-A, inflated to carry radiosonde aloft have average bursting altitudes which decrease as the rate of ascent increases.”
Excerpt from the April 24, 1944  “TM 11-2405 War Department Technical Manual: Meteorological Balloons”. (Image credit: Graphic: NOAA Heritage)
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Do You Know What This Is?

NOAA’s staff recently found this box among old, historic items and are trying to determine what it is. It’s a WWII-era balloon, as the box states, but we don’t know much else about it. Can you help?

We’d like to know:

  1. Who used it and for what?
  2. Are there any historical events that this kind of balloon was involved in?
  3. Is there anything else special about it?
Have an idea for an artifact, photo, or document from NOAA’s history that you think we should feature in Friday Finds? Send an email with a description and, if possible, a photo to heritage.program@noaa.gov.

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NOAA Heritage Homepage

Black and white photo of a woman launching a weather balloon.