Figure 4. Aime' recording thermometer devised by the Frenchman George Aime' at the College of Algeria in 1845. This thermometer was an improvement over the Six's maximum and minimum thermometers and was designed for deployment in the deepest depths of the Mediterranean. He added two reservoirs for the mercury on the bottom to facilitate the mercury staying over the index.

Figure 5. Aime' minimum temperature recording thermometer presented to the Academy of Sciences in Paris in 1844 and described by Aime' in 1845. This instrument differed little from the preceding but at a small point where the fluid enters into the reservoir. This is a reproduction by Negretti and Zambra in 1913.

Figure 6. Aime' maximum temperature recording thermometer. This thermometer was constructed in 1913 as a facscimile of the earlier thermometer by Negretti and Zambra.

Figure 7. Aime' minimum temperature recording thermometer. This thermometer was designed to be made to turn over at the desired depth and retain the minimal temperature reading at that depth while returning to the surface. Aime' is the originator of the concept of the reversing thermometer.

Figure 8. Aime' maximum temperature recording thermometer. He described this instrument in 1845 and it operated in a similar manner to the minimum thermomete r.

Figure 9. Walferdin maximum temperature thermometer a form of reversing thermom ter designed by Francois Walferdin, a French customs official who was responsibl e for in 1855.

Figure 10. Protected Six thermometer constructed by Negretti and Zambra in 1857 . This type of thermometer protected the reservoir of mercury against the effec ts of pressure by having a second glass envelope which inhibited the heating effect of the pressure.

Figure 10 (cont). Protected Six thermometer constructed by Negretti and Zambra in 1857 on its ebonite support.

Figure 11. Six's thermometer, Miller and Casella, 1869 model. This thermometer was made at the request of Doctor William Miller, vice-presiden t of the Royal Society, and produced by the firm of Louis Casella. This thermometer was designed to resist the effects of pressure. This instrument was first used in May 1869.

Figure 11 (cont). Six's thermometer, Miller and Casella, 1869 model. The thermometer is mounted on an ebonite support.

Plate I. Modern reversing thermometers for use in the deep sea. I: Negretti and Zambra. II: F. C.Jacob. IIIa: V. Chabaud. IV: C. Richter.

Figure 12. Negretti and Zambra thermometer, 1874 model. Although the principle of reversing was first described by George Aime' in 1845, this was the first thermometer to accurately determine the temperature at great depth and return to the surface and retain its readings. As such, it is considered the first modern reversing thermometer. It was used on the CHALLENGER expedition.

Figure 13. Negretti and Zambra thermometer, 1878 model. This instrument is the direct ancestor of most reversing thermometers used up to this time. This was the first instrument to break the column of mercury after reversing to obtain the reading. It was entirely enclosed in a double envelope of glass to eliminate pressure effects.

Figure 14. Negretti and Zambra thermometers, older models. These were reversing thermometers completely protected by an outer glass casing. This type of thermometer was manufactured from 1878 until 1912. The scales were graduate d in degrees and half-degree centigrade. Length of these thermometers was about 24 cm, diameter of reservoir about 1.1 cm, and diameter of tube about 1.3 cm.

Figure 14 (cont). Negretti and Zambra thermometers, older models. These were reversing thermometers completely protected by an outer glass casing. This type of thermometer was manufactured from 1878 until 1912. The scales were graduated in degrees and half-degree centigrade. Temperature range of: 99 0034, -26 to 34C; 99 0044, -13 to 35C; 99 0047, -18 to 33C; 99 0052, -7 to 33C.

Figure 15. Negretti and Zambra thermometers, 1912 models. In 1912 a new model of reversing thermometer was introduced which had a number of improvements that increased the sensitivity and accuracy of measurements including a scale that was graduated in 0.2C increments. These instruments had a smaller temperature range than the older instruments at the low end only reading to -2 to -3C.

Figure 16. Certificate of examination certifying that the instruments had been tested at 3 tons pressure and the indicated corrections to readings thashould be used. These instruments were designed for use in polar areas and had temperature scales ranging from about -8C to 16C.

Figure 17. Negretti and Zambra thermometers, 1926 models. These instruments are very similar to thermometers produced by Richter and Wiese in 1925 for the German METEOR expedition. Whether developed independently or copied, they are the same in all details.

Figure 18. Protected Chabaud thermometers constructed by Victor Chabaud in 1892. Three left-most: mercury thermometers. Right: with copper powder.

Figure 18 (cont). Certificate from the Central meteorological bureau with notes concerning the designated thermometers.

Figure 18 (end). Chabaud thermometers. These thermometers were constructed by Victor Chabaud. The three left-most thermometers are in their protective glass envelopes while the two right-most are shown with the protective tube removed.

Figure 19. Hemot thermometer constructed by Alphonse Hemot. Hemot was an instrument maker who made barometers but probably at the request of Prince Albert I of Monaco, he constructed reversing thermometers based on the Chabaud models. It is certain that these thermometers were used on board the PRINCESSE- ALICE II by 1902.

Figure 20. Dumaige thermometer constructed by Paul Dumaige who was a long-time collaborator with the Prince of Monaco. Duimage was known for having constructe d the closing mechanism for a plankton net used by Albert I. It is not known whether this instrument was a copy of an existing instruments or if it was made to improve certain shortcomings. Two of them were used in 1892 at 4808 meters.

Figure 21. Knudsen thermometer invented in 1896 by the Danish professor Martin Knudsen, this model was not much different than the Chabaud thermometer. This instrument was used in the second expedition of the INGOLF in 1896.

Figure 22. Richter thermometer constructed by the German instrument maker Carl Richter following the suggestions of Fridtjof Nansen. Two of these were received in March 1901 and sent to Roald Amundsen for testing in Arctic waters. Although not a revolutionary design, this instrument had many improvements that were followed for tens of years.

Figure 22 (cont). Richter thermometers constructed by the German instrument maker Carl Richter following the suggestions of Fridtjof Nansen. Two of these were received in March 1901 and sent to Roald Amundsen for testing in Arctic waters. Although not a revolutionary design, this instrument had many improvements that were followed for tens of years.

Figure 22 (end). Richter thermometer with its examination certificate.

Figure 22 (end). Correction information accompanying the certificate of examination and also information concerning the circumstances of testing.

Figure 23. Kohler thermometers. These instruments were constructed by Fritz Kohler, who worked notably for the Wilhelm Ostwald Institute at Leipzig. He fabricated these models more or less following the design of Richter's thermometer.

Figure 24. Vereinigte Fabriken fur Laboratoriumsbedarf thermometer, manufactured by the firm of the same name. Vereinigte Fabriken fur Laboratorium sbedarf was a manufacturing concern that made all sorts of instruments for laboratories and researchers. This type of thermometer was made in 1910 after the design of the Richter thermometer.

Figure 25. Schmidt thermometer. These were of the Richter design. The firm of of Schmidt and Vossberg was founded in 1912 and fabricated these instruments upon its debut. Afterwards the company became named solely "Franz Schmidt" and all thermometers of either name are generally grouped under the name Schmidt.

Figure 25 (cont). Examination certificate accompanying Schmidt and Vossberg thermometer dated 13 July, 1913.

Figure 26. Richter and Wiese thermometer, protected model with its certificate of construction. The prototypes of this type of thermometer were used on the German METEOR expedition from 1925-1927.

Figure 26 (cont). Certificate of construction for a Richter and Wiese protected thermometer.

Figure 27. Richter and Wiese unprotected thermometer.

Figure 27 (cont). Front of examination certificate for Richter and Wiese unprotected thermometer.

Figure 27 (end). Front of examination certificate for Richter and Wiese unprotected thermometer.

Figure 28. Gohla thermometer, an unprotected model. For many years the firm of Kurt Gohla made thermometers after the design of Richter and Wiese.

Figure 29. Watanabe thermometer constructed by the Japanese firm Watanabe. This thermometer follows the Richter and Weise design which was used world-wide because of its precision and surety of results.

Mercury thermometers in the collection of the Oceanographic Museum at Monaco. These thermometers were used on board the ships of Prince Albert 1st of Monaco.

Figure 30. Fuess surface thermometer built by Rudolph Fuess of Berlin about 1900. This thermometer acted in the same way as an ordinary thermometer but was meant to be used for measuring the surface waters of the sea.

Figure 31. Flat model surface thermometer. Although this thermometer is named "Richard thermometer" in the museum collections, this is probably an error. The accompanying certificate identifies it as being made by Fritz Kohler of the Ostwald Institute in 1910. It was probably meant to measure the temperature of water acquired with a surface sampling bucket.

Figure 32. Richter surface thermometer, used for measuring the surface waters of the sea. This model was constructed in 1911 by Carl Richter in Berlin. Little is known as to when and where this instrument was tested and used. Undoubtedly it was meant to measure the temperature of water acquired with a surface sampling bucket.

Figure 33. Meyer slow registering thermometer invented by Dr. Adolph Meyer and first used on the POMMERANIA in 1871 and then by various German scientific studies. It was used down to 50 meters but would stay submerged for about an hour to register the proper temperature because it was highly insulated.

Figure 34. Thermometer used with Pettersson-Nansen insulation bottle. This bottle was a version of the Pettersson bottle with improvements made by Fridtjof Nansen in 1900. This thermometer was fixed to the inside cover of the bottle while a reversing thermometer was mounted on the outside. It was first tested on board the MICHAEL SARS in the Norwegian Sea in 3000 meters in 1900.

Figure 35. Muller thermometer constructed by Gustav Muller for laboratory and research studies. It acted as a "normal" thermometer which was used with the Pettersson-Nansen insulation bottle. Because of the time for the temperature to equilibrate in the insulation bottle, the time to take a measurement was prolonged.

Figure 36. Nansen thermometer for use with a water sampling bottle. This thermometer was conceived by Fridtjof Nansen in collaboration with Vagn W. Ekman . This was not a reversing thermometer but was used in an insulated bottle and then brought back to the surface for reading. It was tested on the FRITHJOF in 1910 at many hundreds of meters.

Figure 37. Jacob thermometer devised by Martin Knudsen and constructed by Friedrich C. Jacob of Copenhagen. This thermometer was mounted inside an insula ted bottle that was lowered from an underway ship. This thermometer was of a classic design that had nothing particularly new.

Figure 38. Knudsen thermometer devised by Martin Knudsen for use with an insulated water sampling bottle. Little is known about the testing or use of this thermometer.

Figure 39. Knudsen thermometer constructed by the firm of Siebert and Kuhn. Little is known about this instrument.