We all often use such a device as a thermometer in our lives, but few people know the history of its invention and improvement. It is generally accepted that the thermometer was invented by Galileo Galilei in the distant 1592. The design of the thermoscope (this is what the thermometer was then called) was primitive (see the figure below): a thin glass tube was soldered to a glass ball of small diameter, which was placed in a liquid.

The air in the glass ball was heated by means of a burner or by simple rubbing with the palms, as a result of which it began to displace the liquid in the glass tube, thereby showing the degree of temperature increase: the higher the air temperature in the glass ball became, the lower the water level in the tube fell. An important role was played by the ratio of the volume of the ball to the diameter of the tube: by creating a thinner tube, it was possible to track more insignificant temperature changes in the ball.

Later, the design of Galileo's thermoscope was finalized by one of his students, Fernando de Medici. The basic idea was preserved, but Fernando made significant changes that made the thermoscope more like a modern mercury thermometer. A glass ball and a thin tube were also used (see the figure above), but now the tube was soldered not from below, but from above, and the liquid was already poured into the glass ball, while the top of the tube was open. A change in the temperature of the filled liquid (at that time wine alcohol was used as it) led to an increase in its level in the tube. Later, divisions were applied to the tube, i.e. The first calibration of the thermometer was made.

A lot of time has passed since then, and during this period the thermometer has been improved and modernized more than once. Thanks to recent advances in the fields of physics, new approaches to temperature measurement have been developed. Today, various digital thermometers have been created, which are based on the principle of a change in the resistance of a substance with a change in temperature (electric thermometers) or the principle of a change in the level of luminosity, spectrum and other quantities with a change in temperature (optical thermometers).

This is a thermodynamic quantity that determines the degree of heating of the body. Bodies that have a higher temperature are hotter. According to the second law of thermodynamics, the spontaneous transfer of heat is possible only from bodies with a higher to bodies with a lower temperature. In a state of thermal equilibrium, the temperature equalizes in all parts of an arbitrarily complex system. A measure of a change in body temperature can be a change in some property that depends on it, for example, volume, electrical resistance, etc. Most often, a change in volume is used to measure temperature. The device of thermometers is based on this. The first thermometer was invented by Galileo around 1600. As a thermometric substance, i.e., a body that expands when heated, water was used in it. To determine body temperature, the thermometer is brought into contact with the body; when thermal equilibrium is reached, the thermometer shows the temperature of the body. To change the temperature, you can use a bimetallic plate. Such a plate consists of two metals, for example, a strip of iron and a strip of zinc riveted to it. Iron and zinc expand differently. So, 1 m of iron wire, when heated by 100 degrees, lengthens by 1 mm, and 1 m of zinc wire - by 3 mm. Therefore, if a bimetallic plate is heated, it will begin to bend towards the iron.

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There are many temperature scales. A device for measuring temperature was created a long time ago and was called a thermometer.

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The intuitive idea of temperature develops from the first days of our life. However, the tasks facing science require more and more precise interpretations of what we perceive through the senses. Thus, an important stage in the development of the theory of thermal phenomena was the identification of the difference between the concepts of "heat" and "temperature". The first to clearly articulate the idea of the need to distinguish between them was Black. The history of the creation and use of instruments for measuring temperature - thermometers - is interesting and informative. "We must accept as one of the most general laws of heat that "all bodies" freely communicating with each other and not subject to unequal external influences acquire the same temperature, which is indicated by a thermometer. Joseph Black Today, liquid and gas thermometers, semiconductor and optical thermometers are known. And the variety of temperatures now introduced in science is great: they distinguish between electron and ion temperatures, brightness and color, noise and antenna, etc.

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Timeline of the creation of the thermometer

In 1597, Galileo Galilei invented the first device for observing temperature changes (thermoscope). In 1657, Galileo's thermoscope was improved by Florentine scientists. Permanent thermometer points were established in the 18th century. In 1714, the Dutch scientist D. Fahrenheit made a mercury thermometer. In 1730, the French physicist R. Reaumur proposed an alcohol thermometer. In 1848, the English physicist William Thomson (Lord Kelvin) proved the possibility of creating an absolute temperature scale. William Thomson

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Different bodies expand differently when heated, so the scale of a thermometer depends on the thermometric substance. For practical purposes, thermometers are calibrated in terms of melting or boiling points, or some other, so long as the process occurs at a constant temperature. The most common is the centigrade scale (or the Celsius scale, after the Swedish physicist who proposed it). On this scale, ice melts at 0 degrees and water boils at 100 degrees, and the distance between them is divided into one hundred parts, each of which is considered a degree. In England and the USA, the Fahrenheit scale is sometimes used, in which the melting point of ice is 32 degrees, and the boiling point of water is 212 degrees; in France, the Réaumur scale: 0 degrees and 80, respectively. Now for some practical advice. Take strips of iron and zinc about 5 mm thick, 15-20 cm long and 1 cm wide. Connect them with rivets every 1.5-2 cm. Clamp one end of the bimetallic strip in a vise and heat it over the gas. The plate will bend.

Slide 7

Invention of the thermometer

About what heat is, scientists began to think for a very long time. Even the ancient Greek philosophers pondered this question. But they could not express anything but the most general assumptions. Almost no reasonable ideas were expressed in the Middle Ages either. The doctrine of thermal phenomena begins to develop only in the middle of the 18th century. The impetus for the beginning of the development of this doctrine was the invention of the thermometer. Many scientists worked on the invention of the thermometer. The first of these was Galileo Galilei. At the end of the XVI century. Galileo became interested in thermal phenomena. To measure the heat of a body, Galileo decided to use the property of air to expand when heated. He took a thin glass tube, one end of which ended in a ball, and lowered the other open end into a vessel of water. At the same time, he achieved such a position that the water partially filled the tube. Now, when the air in the ball was heated or cooled, the water level in the tube fell or rose, and the water level could be used to judge the “heating” of the body. Galileo's device was very imperfect. Firstly, it was not graduated, no divisions were applied to the tube. Secondly, the water level in the tube depended not only on the temperature of the air in the glass ball, but also on atmospheric pressure.

Slide 8

Improvement of the thermometer

After Galileo, many scientists were engaged in the invention of instruments with which it would be possible to determine the thermal state of bodies. Gradually, the instrumentation was improved. In the middle of the XVII century. The Florentine Academy of Experience proposed the device shown in the figure. The device was a glass tube ending in a ball at the bottom. The upper end of the tube was sealed. The ball and part of the tube were filled with alcohol, and beads were placed along the tube, forming a scale for reading the temperature. The readings of this instrument no longer depended on the value of atmospheric pressure. There were also other thermometers. In particular, one of the first designers was the Italian doctor Santorio, who used his device to measure the temperature of patients. This was probably the first practical use of the thermometer. Despite advances in the design of thermometers, these instruments were still very imperfect: a common temperature scale had not been established; for various thermometers, it was set arbitrarily; different thermometers showed different temperatures under the same conditions.

Slide 9

Fahrenheit thermometer

In his last scale, the main temperature points were as follows: the temperature of a mixture of water, ice and table salt is zero degrees; the temperature of a mixture of ice and water is 32 degrees. The temperature of the human body on the Fahrenheit scale turned out to be 96 degrees. Fahrenheit considered this temperature the third main point. The boiling point of water was 180 degrees on his scale. Thermometers made by Fahrenheit gained fame and came into use. The Fahrenheit scale was used in some countries up to our time. For the first time, thermometers suitable for practical purposes began to be made by a master glass blower from Holland Fahrenheit at the beginning of the 18th century. By this time, scientists already knew that some physical processes always take place at the same degree of heating. The Fahrenheit thermometer looked the same as a modern simple thermometer. As an expanding body, Fahrenheit first used alcohol, and then, in 1714, mercury. He used different scales.

Slide 10

Réaumur and Celsius

After Fahrenheit, many other scales and thermometer designs have been proposed. Of all these scales, two have come down to our time. The first scale: 0 degrees - the temperature of a mixture of water and ice and 80 degrees - the boiling point of water was proposed by the French scientist Réaumur in 1730 and bears his name. The second scale incorrectly bears the name of the Swedish astronomer Celsius. Celsius in 1742 proposed a centigrade temperature scale, in which 0 degrees was taken as the boiling point of water, and 100 degrees as the melting point of ice. The modern centigrade scale, called the Celsius scale, was proposed somewhat later. As you know, it came into use and is currently used. Celsius already knew that the boiling point of water and the melting point of ice depend on air pressure. After the invention of the device for thermal measurements, physicists were able to begin to study thermal phenomena.

slide 11

It is curious that…

... in fact, the Swedish astronomer and physicist Celsius proposed a scale in which the boiling point of water was indicated by the number 0, and the melting point of ice - by the number 100. Somewhat later, the Celsius scale was given a modern look by his compatriot Strömer. ... Fahrenheit got excited about the idea of making a thermometer himself when he read about the discovery of the French physicist Amonton, "that water boils at a fixed degree of heat." ...by the end of the 18th century, the number of temperature scales reached two dozen. ... at one time in physical laboratories they used the so-called weight thermometer. It consisted of a hollow platinum ball filled with mercury, which had a capillary hole. The change in temperature was judged by the amount of mercury flowing out of the hole. … with a decrease in the temperature of the Earth by just one degree, energy would be released that is about a billion times greater than that generated annually by all the power plants in the world.

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Conclusion

The first thermometer was created in the 16th century by Galileo. The most widely used temperature scales are Fahrenheit and Celsius.

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Sources used: B.I. Spassky "Physics in its development", M. "Enlightenment", 1979 "Physics for the young", compiled by M.N. Alekseeva, M. "Enlightenment", 1980 A.A. Leonovich "Physical Kaleidoscope", M. "Bureau Quantum", 1994 "Encyclopedic Dictionary of a Young Physicist", M. "Pedagogy", 1984

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The intuitive idea of temperature develops from the first days of our life. However, the tasks facing science require more and more precise interpretations of what we perceive through the senses. Thus, an important stage in the development of the theory of thermal phenomena was the identification of the difference between the concepts of "heat" and "temperature". The first to clearly articulate the idea of the need to distinguish between them was Black. The history of the creation and use of instruments for measuring temperature - thermometers - is interesting and informative. Today, liquid and gas thermometers, semiconductor and optical thermometers are known. And the variety of temperatures now introduced in science is great: they distinguish between electron and ion temperatures, brightness and color, noise and antenna, etc. "We must accept as one of the most general laws of heat that "all bodies" freely communicating with each other and not subject to unequal external influences acquire the same temperature, which is indicated by a thermometer. Joseph Black Joseph Black

Chronology of the creation of a thermometer In 1597, Galileo Galilei invented the first device for observing temperature changes (thermoscope). In 1657, Galileo's thermoscope was improved by Florentine scientists. Permanent thermometer points were established in the 18th century. In 1714, the Dutch scientist D. Fahrenheit made a mercury thermometer. In 1730, the French physicist R. Reaumur proposed an alcohol thermometer. In 1848, the English physicist William Thomson (Lord Kelvin) proved the possibility of creating an absolute temperature scale. William Thomson

TEMPERATURE This is a thermodynamic quantity that determines the degree of heating of a body. Bodies that have a higher temperature are hotter. According to the second law of thermodynamics, the spontaneous transfer of heat is possible only from bodies with a higher to bodies with a lower temperature. In a state of thermal equilibrium, the temperature equalizes in all parts of an arbitrarily complex system. A measure of a change in body temperature can be a change in some property that depends on it, for example, volume, electrical resistance, etc. Most often, a change in volume is used to measure temperature. The device of thermometers is based on this. The first thermometer was invented by Galileo around 1600. As a thermometric substance, i.e., a body that expands when heated, water was used in it. To determine body temperature, the thermometer is brought into contact with the body; when thermal equilibrium is reached, the thermometer shows the temperature of the body. To change the temperature, you can use a bimetallic plate. Such a plate consists of two metals, for example, a strip of iron and a strip of zinc riveted to it. Iron and zinc expand differently. So, 1 m of iron wire, when heated by 100 degrees, lengthens by 1 mm, and 1 m of zinc wire - by 3 mm. Therefore, if a bimetallic plate is heated, it will begin to bend towards the iron.

Different bodies expand differently when heated, so the scale of a thermometer depends on the thermometric substance. For practical purposes, thermometers are calibrated in terms of melting or boiling points, or some other, so long as the process occurs at a constant temperature. The most common is the centigrade scale (or the Celsius scale, after the Swedish physicist who proposed it). On this scale, ice melts at 0 degrees and water boils at 100 degrees, and the distance between them is divided into one hundred parts, each of which is considered a degree. In England and the USA, the Fahrenheit scale is sometimes used, in which the melting point of ice is 32 degrees, and the boiling point of water is 212 degrees; in France, the Réaumur scale: 0 degrees and 80, respectively. Now for some practical advice. Take strips of iron and zinc about 5 mm thick, cm long and 1 cm wide. Connect them with rivets every cm. Clamp one end of the bimetallic strip in a vise and heat it over the gas. The plate will bend.

The invention of the thermometer Scientists began to think about what heat is a very long time ago. Even the ancient Greek philosophers pondered this question. But they could not express anything but the most general assumptions. Almost no reasonable ideas were expressed in the Middle Ages either. The doctrine of thermal phenomena begins to develop only in the middle of the 18th century. The impetus for the beginning of the development of this doctrine was the invention of the thermometer. Many scientists worked on the invention of the thermometer. The first of these was Galileo Galilei. At the end of the XVI century. Galileo became interested in thermal phenomena. To measure the heat of a body, Galileo decided to use the property of air to expand when heated. He took a thin glass tube, one end of which ended in a ball, and lowered the other open end into a vessel of water. At the same time, he achieved such a position that the water partially filled the tube. Now, when the air in the ball was heated or cooled, the water level in the tube fell or rose, and the water level could be used to judge the “heating” of the body. Galileo's device was very imperfect. Firstly, it was not graduated, no divisions were applied to the tube. Secondly, the water level in the tube depended not only on the temperature of the air in the glass ball, but also on atmospheric pressure.

Improvement of the thermometer After Galileo, many scientists were engaged in the invention of devices with which it would be possible to determine the thermal state of bodies. Gradually, the instrumentation was improved. In the middle of the XVII century. The Florentine Academy of Experience proposed the device shown in the figure. The device was a glass tube ending in a ball at the bottom. The upper end of the tube was sealed. The ball and part of the tube were filled with alcohol, and beads were placed along the tube, forming a scale for reading the temperature. The readings of this instrument no longer depended on the value of atmospheric pressure. There were also other thermometers. In particular, one of the first designers was the Italian doctor Santorio, who used his device to measure the temperature of patients. This was probably the first practical use of the thermometer. Despite advances in the design of thermometers, these instruments were still very imperfect: a common temperature scale had not been established; for various thermometers, it was set arbitrarily; different thermometers showed different temperatures under the same conditions.

Fahrenheit thermometer For the first time thermometers suitable for practical purposes began to be made by a master glass blower from Holland Fahrenheit at the beginning of the 18th century. By this time, scientists already knew that some physical processes always take place at the same degree of heating. The Fahrenheit thermometer looked the same as a modern simple thermometer. As an expanding body, Fahrenheit first used alcohol, and then, in 1714, mercury. He used different scales. In his latest scale, the main temperature points were as follows: 1. temperature of a mixture of water, ice and table salt - zero degrees 2. temperature of a mixture of ice and water - 32 degrees. The temperature of the human body on the Fahrenheit scale turned out to be 96 degrees. Fahrenheit considered this temperature the third main point. The boiling point of water was 180 degrees on his scale. Thermometers made by Fahrenheit gained fame and came into use. The Fahrenheit scale has been used in some countries up to our time.

Réaumur and Celsius After Fahrenheit, many other scales and thermometer designs have been proposed. Of all these scales, two have come down to our time. The first scale: 0 degrees - the temperature of a mixture of water and ice and 80 degrees - the boiling point of water was proposed by the French scientist Réaumur in 1730 and bears his name. The second scale incorrectly bears the name of the Swedish astronomer Celsius. Celsius in 1742 proposed a centigrade temperature scale, in which 0 degrees was taken as the boiling point of water, and 100 degrees as the melting point of ice. The modern centigrade scale, called the Celsius scale, was proposed somewhat later. As you know, it came into use and is currently used. Celsius already knew that the boiling point of water and the melting point of ice depend on air pressure. After the invention of the device for thermal measurements, physicists were able to begin to study thermal phenomena.

It is curious that ... ... in fact, the Swedish astronomer and physicist Celsius proposed a scale in which the boiling point of water was indicated by the number 0, and the melting point of ice - by the number 100. Somewhat later, the Celsius scale was given a modern look by his compatriot Strömer. ... Fahrenheit got excited about the idea of making a thermometer himself when he read about the discovery of the French physicist Amonton, "that water boils at a fixed degree of heat." ...by the end of the 18th century, the number of temperature scales reached two dozen. ... at one time in physical laboratories they used the so-called weight thermometer. It consisted of a hollow platinum ball filled with mercury, which had a capillary hole. The change in temperature was judged by the amount of mercury flowing out of the hole. … with a decrease in the temperature of the Earth by just one degree, energy would be released that is about a billion times greater than that generated annually by all the power plants in the world.

Literature B.I. Spassky "Physics in its development", M. "Enlightenment", 1979 "Physics for the young", compiled by M.N. Alekseeva, M. "Enlightenment", 1980 A.A. Leonovich "Physical Kaleidoscope", M. "Bureau Quantum", 1994 "Encyclopedic Dictionary of a Young Physicist", M. "Pedagogy", 1984

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"We must accept as one of the most general laws of heat that "all bodies" freely communicating with each other and not subject to unequal external influences acquire the same temperature, which is indicated by a thermometer. Joseph Black Intuition about temperature develops from the first days of our life. However, the tasks facing science require more and more accurate interpretations of what we comprehend by the senses. Thus, an important stage in the development of the theory of thermal phenomena was the identification of the difference between the concepts of "heat" and "temperature". The first to clearly articulate the idea of the need to distinguish between them was Black. An interesting and informative history of the creation and use of devices for measuring temperature - thermometers. Today, liquid and gas thermometers, semiconductor and optical thermometers are known. And the variety of temperatures now introduced in science is great: they distinguish between electron and ion temperatures, brightness and color, noise and antenna, etc.

slide number 4

Description of the slide:

Chronology of the creation of a thermometer In 1597, Galileo Galilei invented the first device for observing temperature changes (thermoscope) In 1657, Galileo's thermoscope was improved by Florentine scientists. The constant points of the thermometer were established in the 18th century. mercury thermometer. In 1730, the French physicist R. Reaumur proposed an alcohol thermometer. In 1848, the English physicist William Thomson (Lord Kelvin) proved the possibility of creating an absolute temperature scale. William Thomson

slide number 5

Description of the slide:

Temperature This is a thermodynamic quantity that determines the degree of heating of the body. Bodies that have a higher temperature are hotter. According to the second law of thermodynamics, the spontaneous transfer of heat is possible only from bodies with a higher to bodies with a lower temperature. In a state of thermal equilibrium, the temperature equalizes in all parts of an arbitrarily complex system. A change in a property that depends on it, for example, volume, electrical resistance, etc., can serve as a measure of a change in body temperature. Most often, a change in volume is used to measure temperature. The device of thermometers is based on this. The first thermometer was invented by Galileo around 1600. As a thermometric substance, i.e., a body that expands when heated, water was used in it. To determine body temperature, the thermometer is brought into contact with the body; upon reaching thermal equilibrium, the thermometer shows the temperature of the body. To change the temperature, you can use a bimetallic plate. Such a plate consists of two metals, for example, a strip of iron and a strip of zinc riveted to it. Iron and zinc expand differently. So, 1 m of iron wire, when heated by 100 degrees, lengthens by 1 mm, and 1 m of zinc wire - by 3 mm. Therefore, if a bimetallic plate is heated, it will begin to bend towards the iron.

slide number 6

Description of the slide:

Different bodies expand differently when heated, so the scale of a thermometer depends on the thermometric substance. For practical purposes, thermometers are calibrated in terms of melting or boiling points, or some other, so long as the process occurs at a constant temperature. The most common is the centigrade scale (or the Celsius scale, after the Swedish physicist who proposed it). On this scale, ice melts at 0 degrees and water boils at 100 degrees, and the distance between them is divided into one hundred parts, each of which is considered a degree. In England and the USA, the Fahrenheit scale is sometimes used, in which the melting point of ice is 32 degrees, and the boiling point of water is 212 degrees; in France, the Reaumur scale: 0 degrees and 80, respectively. Now a few practical tips. Take strips of iron and zinc about 5 mm thick, 15-20 cm long and 1 cm wide. Connect them with rivets every 1.5-2 cm. Clamp one end of the bimetallic strip in a vise and heat it over the gas. The plate will bend.

slide number 7

Description of the slide:

The invention of the thermometer Scientists began to think about what heat is a very long time ago. Even the ancient Greek philosophers pondered this issue. But they could not express anything but the most general assumptions. In the Middle Ages, almost no reasonable ideas were expressed either. The doctrine of thermal phenomena begins to develop only in the middle of the 18th century. The impetus for the beginning of the development of this doctrine was the invention of the thermometer. Many scientists worked on the invention of the thermometer. The first of these was Galileo Galilei. At the end of the XVI century. Galileo became interested in thermal phenomena. To measure the heat of a body, Galileo decided to use the property of air to expand when heated. He took a thin glass tube, one end of which ended in a ball, and lowered the other open end into a vessel of water. At the same time, he achieved such a position that the water partially filled the tube. Now, when the air in the ball was heated or cooled, the water level in the tube fell or rose, and the water level could be used to judge the “heating” of the body. Galileo's device was very imperfect. Firstly, it was not graduated, no divisions were applied to the tube. Secondly, the water level in the tube depended not only on the temperature of the air in the glass ball, but also on atmospheric pressure.

slide number 8

Description of the slide:

Improvement of the thermometer After Galileo, many scientists were engaged in the invention of devices with which it would be possible to determine the thermal state of bodies. Gradually, the instrumentation was improved. In the middle of the XVII century. The Florentine Academy of Experience proposed the device shown in the figure. The device was a glass tube ending in a ball at the bottom. The upper end of the tube was sealed. The ball and part of the tube were filled with alcohol, and beads were placed along the tube, forming a scale for reading the temperature. The readings of this instrument no longer depended on the value of atmospheric pressure. There were also other thermometers. In particular, one of the first designers was the Italian doctor Santorio, who used his device to measure the temperature of patients. This was probably the first practical use of a thermometer. Despite advances in the design of thermometers, these instruments were still very imperfect: a common temperature scale had not been established; for various thermometers, it was set arbitrarily; different thermometers showed different temperatures under the same conditions.

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Description of the slide:

Fahrenheit thermometer For the first time thermometers suitable for practical purposes began to be made by a master glass blower from Holland Fahrenheit at the beginning of the 18th century. By this time, scientists already knew that some physical processes always proceed at the same degree of heating. The Fahrenheit thermometer looked the same as a modern simple thermometer. As an expanding body, Fahrenheit first used alcohol, and then, in 1714, mercury. He used various scales. In his last scale, the main temperature points were as follows: the temperature of a mixture of water, ice and table salt is zero degrees; the temperature of a mixture of ice and water is 32 degrees. The temperature of the human body on the Fahrenheit scale turned out to be 96 degrees. Fahrenheit considered this temperature the third main point. The boiling point of water was 180 degrees on his scale. Thermometers made by Fahrenheit gained fame and came into use. The Fahrenheit scale was used in some countries up to our time.

slide number 10

Description of the slide:

slide number 11

Description of the slide:

It is curious that ... ... in fact, the Swedish astronomer and physicist Celsius proposed a scale in which the boiling point of water was indicated by the number 0, and the melting point of ice - by the number 100. Somewhat later, the Celsius scale was given a modern look by his compatriot Strömer. ... Fahrenheit caught fire with the idea himself to make a thermometer when I read about the discovery of the French physicist Amonton, “that water boils at a fixed degree of heat” ... by the end of the 18th century, the number of temperature scales reached two dozen ... at one time in physical laboratories they used the so-called weight thermometer. It consisted of a hollow platinum ball filled with mercury, which had a capillary hole. The change in temperature was judged by the amount of mercury flowing out of the hole ... if the temperature of the Earth dropped by just one degree, energy would be released, about a billion times greater than that generated annually by all the power plants in the world.