Thermometer Timeline
Body temperature, like most other scientific medical phenomena, was always intriguing to health professionals. But, as thermometers in general were developed in an attempt to study and understand temperature, they were originally designed to measure the external climate temperature. With time, research, and a greater understanding of disease, thermometers were developed for use in discovering the fluctuations of human body temperature. A cascade of changes and innovations followed in an attempt to improve accuracy and ease of use of the instrument.
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The following is a list of the many innovations that thermometers have undergone.
1700 B.C.E.
the hand used as a thermometer, primarily on the brow (forehead).
1592-1603
Galileo conducted experiments based on the expansion of air with heat. The Instrument was named the Thermoscope.
Early 1600's
De Haen of Vienna introduces the thermometer to medicine. The thermometers use in medicine fell in usage after his death.
1612
Santorio Santorio added a numerical scale to the outside of the instrument for improved analysis of temperature change
1631
Jean Rey, a French physicist, invented the first water expansion thermometer
1641
The Duke Ferdinand II of Tuscany sealed the thermometer to remove the impact of air pressure on the instruments measurements
1709
Daniel Fahrenheit invented a thermometer filled with alcohol
1714
Daniel Fahrenheit invented another thermometer, this time filled with mercury as it expanded and contracted evenly over a large temperature range
1742
Anders Celsius developed his temperature scale
1820-1823
Experiments occurred for the development of what would become, in the next century, the electric thermometer
Early 1850's
Aitken developed the contraction of the thermometer so that the maximum recording could be held after removing the thermometer from the body, increasing accuracy and use
1866
Dr. Thomas Clifford introduced a smaller 6 inch thermometer (replacing the old ones which could be up to a meter in length)
1867
Allbutt introduced an even smaller thermometer that was only 3 inches in length
1868
Karl Wunderlich published his research on the fluctuations in body temperature for over 25 000 patients. Thomas Maclagan also published research on the temperatures of patients with typhus, typhoid, and pneumonia. Their research revolutionised the concept of the importance of temperature for the body and its relation to disease.
1878
Peroni patented a triangular thermometer. They were less likely to roll of a flat surface and the shape magnified the mercury tube as well as the scales so tat the temperature could be read easier.
1890
Dr. Schott invented Jena Normal glass. This innovation prolonged the life and the accuracy of thermometers
1980's
Infrared thermometers are introduced into the medical field as a reliable, less invasive means of a assessing a patient's temperature
1984
Celsius was determined to be the scale of choice by at the 9th General Conference of Weights and Measures
1991
Mercury thermometers are banned for use in public medicine due to their environmental impact and the possibility of breakage for a patient
This timeline is not complete as there are other inventions and research that have contributed to the physical evolution of the thermometer. Additionally, the attempt to make this a linear progression with clear defined dates excludes larger trends in research, sanitation, care and use.
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To read more on the transition of the thermometer into medicine read here.
To read more on sanitation and care, read here.
