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A Unique Perspective on Weather

April 12, 2012

The Black Box

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Maintaining weather records was a popular pastime when the Almanac began. Many U.S. presidents, for example, Thomas Jefferson, owned their own weather instruments, from which they recorded daily observations.

A Secret Formula

As many of you know, we at The Old Farmer’s Almanac continue to derive our weather forecasts from a secret formula that was devised by the founder of this Almanac, Robert B. Thomas, in 1792.

Even today, Robert’s formula is kept safely tucked away in a black tin box at the Almanac offices in Dublin, New Hampshire. (Yes, that's a photo of the unassuming black box at the top.)

Mysterious Weather Predictors

With excitement, we recently learned about other “mysterious” but surprisingly accurate weather predictors that were used in the 1700s and 1800s. They are still being handcrafted today by a small, 80-year-old company Weems & Plath in Annapolis, Maryland.

And if you are purchasing a very special holiday gift for a loved one, you can learn more about these unique weather instruments in The Old Farmer’s Almanac General Store.

The Stormglass

In December of 1831, Admiral Fitzroy, the famous sailor and meteorologist, took a historic voyage with Darwin to the Galápagos Islands.

Mounted on the mast of the HMS Beagle was an instrument called a "stormglass," which was used to predict weather 1 to 2 days in advance.

Photo: The Weems Stormglass—Note the black box!

The premise of the stormglass is that changing weather affects the solubility of the mixture of chemicals in a sealed glass tube. Some believe that the changes in crystal structures have to do with the electromagnetic changes caused by weather and Sun storms.

The sealed glass chamber holds the crystals of the stormglass and is encapsulated in a beautifully crafted brass cylinder. It’s a “low-tech” device that requires no batteries or programming, and it works indoors and out.

Jeffersonian Instruments

Thomas Jefferson’s affinity for mechanical invention is well known. If you love weather, you’ll be fascinated by these distinctive heirloom-quality weather instruments that are inspired by Jefferson: an Outdoor Thermometer, Rain Gauge, and Wind Gauge.

The Jeffersonian Outdoor Thermometer uses a unique pierced brass drum scale with separate Fahrenheit and Celsius temperature scales to allow reading from either side of the instrument. A large isolated bi-metal coil on the thermometer provides an accurate reading even in full sunlight! We think that it would make a striking accent in the garden.

Photo: The Jeffersonian Outdoor Thermometer

The Jeffersonian Rain Gauge (in front) is quite a statement maker! This intriguing brass instrument uses a float and lever design to measure up to 5 inches of rain in 1/5-inch increments. As rain fills the vial of the brass gauge, the red ball rises, consequently causing the stainless steel arm to climb up the 5-inch scale.

Photo: The Jeffersonian Rain Gauge

The Jeffersonian Wind Gauge measures both wind speed and direction. Ever been outside and wondered just how fast the wind was blowing? The stainless steel pointer displays wind speeds up to 40 miles per hour. The cobalt blue glass counterbalance points out the wind direction on the wind gauge while acting as a damper to keep the speed indicator steady. Made of solid brass, glass, and stainless steel, the gauge is rust-resistant, and its antiqued finish takes on a beautiful patina over the years.

Photo: The Jeffersonian Wind Gauge

We hope you find these weather instruments as interesting as we do! Not only are they practical, but they add a touch of history to your yard, garden, or office. Their beauty also makes them functional art for your outdoor space.

You can learn more about Jeffersonian outdoor weather instruments—and other inventive devices—in the The Old Farmer's Almanac General Store.
We wish you all wondrous weather watching!

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Catherine, our New Media Editor, joined The Old Farmer's Almanac in 2008. She edits content on both this Web site,, and the companion site to The Old Farmer's Almanac for Kids publication, She also pens the Almanac Companion enewsletters and keeps up with readers on Facebook, Twitter, and Pinterest!


the Thomas Jefferson weather

By Francis Koster Ed. D.

the Thomas Jefferson weather guages do not have a published price, and when I click on "Buy Now" nothing happens.

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