Which Galileo thermometer is best?
Named for the famous Italian scientist, a Galileo thermometer is a functional and aesthetically pleasing way to tell the temperature in your home. This centuries-old device is typically cylindrical in shape, filled with liquid and floating glass bulbs that indicate the current temperature.
The Wind & Weather Galileo Weather Station is a comprehensive instrument pairing a thermometer with additional useful measurements. Finding the best Galileo thermometer requires an understanding of operation, limitations and design choices available.
What to know before you buy a Galileo thermometer
The Galileo thermometer was invented in the mid-17th century by an academic collective at Accademia del Cimento in Florence, Italy. While Galileo was not a part of this group, the creation was inspired by his work — namely the thermoscope, which tracked temperature changes.
The Galileo thermometer may look complex upon initial viewing, but the principles are fairly simple. A glass container, usually a cylinder, is filled with liquid, often mineral oil, with numerous small glass bulbs floating within. While they are all the same size and density, each is attached to a different weight with a corresponding number.
As the temperature changes in the room, the liquid temperature changes, which influences its density. As a result, the weighted bulbs will float, sink or suspend in the center of the cylinder. The lone bulb closest to the middle indicates the current temperature: read the number on the weight to get a close approximation.
Galileo thermometers aren’t ideal for tracking extreme temperatures. They are designed for regular use indoors, or briefly outside in moderate weather. Because there are only so many bulbs within — typically five — temperature range is fairly limited. Precision is also an issue, as bulbs are often labeled in increments of four or five degrees.
What to look for in a quality Galileo thermometer
These instruments do not have a uniform size; the height and diameter of the cylinder do not affect how the invention operates. Size only influences where you can suitably place the thermometer and how it looks. Most stand between 8 and 16 inches high with a relatively small diameter and slender base. Some instruments may come with a hook or handle on top that allow them to be hung.
The basic Galileo thermometer offers a temperature range from 64 to 80 degrees. These will feature five bulbs in increments of four degrees.
Larger models are also available, which may widen the range in either direction and, as a result, add to the number of bulbs within.
Some thermometers are embedded within a larger installation that includes additional devices and other measurements. A Galileo thermometer may be incorporated alongside a barometer, which reads pressure, or a hygrometer that tracks vapor water in the air. Some may also come with an analog clock for an antique look.
While most bulbs only include readings in Fahrenheit, some will also offer Celsius as well.
The typical shape is cylindrical, but there are also some spherical designs available for those seeking an alternative aesthetic. The shape does not influence the accuracy of the reading.
Each bulb has a distinct color to enhance the look of the thermometer. Color does not affect operation. Red, yellow, green and blue are standard, but some may feature bolder shades or even pastel colors. For those seeking a modern look, opt for a thermometer that features black liquid in every bulb.
How much you can expect to spend on a Galileo thermometer
Expect to spend $25-$50, depending on size and number of bulbs included.
Galileo thermometer FAQ
What if there is no bulb floating in the middle?
A. The central bulb offers the most accurate reading, but sometimes there will not be a bulb in the middle. Occasionally bulbs will cluster at both the top and the bottom, which means the temperature is somewhere in between. To calculate, note the lowest hanging number from the top group and the highest floating bulb from the lower group. Add the two numbers together and divide by two to obtain the most accurate temperature reading.
If all the bulbs are at the bottom, the temperature is hotter than the bulb with the highest number. Conversely, with all bulbs clustered at the top, the temperature will be colder than the lowest number available.
Is the thermometer safe for use outside?
A. Galileo thermometers can be used outside with certain precautions and tempered expectations. Due to their limited range, they won’t effectively measure hot summer days or cold autumn mornings with any accuracy. They are also delicate, so they may not hold up well in windy conditions. As it only takes minutes for the thermometer to obtain a reading, it can be brought outdoors momentarily but should not be left unattended for long periods.
What’s the best Galileo thermometer to buy?
Top Galileo thermometer
What you need to know: A Galileo thermometer is included alongside other useful measurements in this elaborate, eye-catching arrangement.
What you’ll love: Featuring a clock, barometer and hygrometer with the Galileo thermometer, this impressive weather station is elegant and sophisticated. The dark wood base provides a refined aesthetic.
What you should consider: The inclusion of additional devices raises the price substantially.
Where to buy: Sold by Amazon
Top Galileo thermometer for the money
What you need to know: A simple yet attractive Galileo thermometer, this standard design comes at a low price and fits with any home decor.
What you’ll love: This is a quintessential modern Galileo thermometer, with five colored bulbs measuring temperature from 64 to 80 degrees. The base is sturdy and the design allows for placement around the home.
What you should consider: At 14 inches, the thermometer is fairly tall.
Where to buy: Sold by Amazon
Worth checking out
What you need to know: This stunning model features the standard cylindrical Galileo thermometer alongside a spherical glass barometer.
What you’ll love: The Galileo thermometer and barometer are joined by a stable, wooden base. Both glass instruments provide a stunning presence in the home as well as useful information about the weather.
What you should consider: These two instruments are relatively fragile.
Where to buy: Sold by Amazon
Sign up here to receive the BestReviews weekly newsletter for useful advice on new products and noteworthy deals.
Anthony Marcusa writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.
Copyright 2022 BestReviews, a Nexstar company. All rights reserved.