Figure 38. Hinged messenger, a model first proposed by the hydrographic laboratory at Copenhagen in 1914. The models shown are of a later date.

Figure 39. Spiral opening messenger - in the design of these messengers, the groove which allows the device to be placed on the cable is in the form of an S or Z. The messenger is locked on the cable by means of a rotating part at the top of the messenger. A simpler non-locking version of this messenger was produced by HYTECH, a California firm.

Figure 40. Thoulet soluble cartridge messenger for delayed release of instruments. These "soluble weights" were designed to initiate the functioning of an immersed device at a pre-determined time. Thoulet had apparently designed this device for use with sampling nets . He started tests with these in 1893 in Lake Gerardmer and provided samples for Prince Albert I to use at sea.

Figure 41. Kiel Commission Hydrometers - these hydrometers were created in 1870 at the initiative of the Commission of Scientific Studies of German Waters at Kiel.

Figure 42. Buchanan hydrometer made at the request of John Y. Buchanan during the CHALLENGER Expedition. These were instruments with variable weight and volume. Two of these instruments were improved and modified by Victor Chabaud and used during the Belgium Antarctic Expedition from the BELGICA from 1897 to 1899.

Figure 42 (continued.) Various Buchanan hydrometers with associated apparatus in their instrument cases.

Figure 42 (end.) A Buchanan hydrometer instrument case with the initials of John Y. Buchanan.

Figure 43. Nansen total immersion hydrometer, an instrument of variable weight and constant volume. The fact that the instrument is completely immersed during use explains the term "constant volume." Its principle was first put forth by Giuseppe Pisati in 1890 and adopted by Fridthof Nansen in 1900. In 1901 it was used by Jacob Schetelig, Nansen's assistant, from the MICHAEL SARS.

Figure 44. Thoulet total immersion hydrometer, designed by Professor Julien Thoulet for the purpose of studying the density of water from depth for the purpose of studying sub-surface currents. Professor Thoulet produced this relatively small sampling device of 200 cubic centimeter volume with Professor Henry Adolpe Chevalier of the University of Nancy.

Figure 45. Pettersson small chain hydrometer, designed by Professors Otto and Hans Pettersson in 1917. This instrument eliminated difficulties associated with the surface tension of the sample as well as variations of volume. A small metal chain helped achieve a balance by compensating for the buoyancy of the float as a function of the density of the liquid.

Figure 46. Regnault pycnometers, instruments first mentioned by the physicist Henri-Victor Regnault, a professor at the College of France, in 1843. These instruments were used to measure the density of liquids which he was studying to obtain their specific heat.

Figure 47. Sprengel pycnometer, first described by the German chemist Hermann Sprengel in 1873. He had used this instrument for a number of years. It had great precision and was easy to fill. Later the German chemist Wilhelm Ostwald partially modified it, replacing the original U tube with a single-sided one.

Figure 48. Knudsen pycnometer, described by the Danish physicist and hydrographer Martin Knudsen in 1902. This instrument was designed to make precise laboratory measurements of the density of sea water.

Figure 49. Fery refractometer, an instrument first suggested by Julius Hilgard of the United States Coast and Geodetic Survey to measure the density of sea water by relating the index of refraction of a liquid to its density. The instrument shown was developed by the Frenchman Charles Fery in 1891.

Figure 50. Berget double deviation refractometer, developed and devised by the Frenchman Alphonse Berget, professor at the Oceanographic Institute. From about 1911 onward, he was concerned with developing an instrument to measure the density of a liquid at sea by a method that would not be affected by the ship's motion. He described the pictured instrument in 1925.

Plate 4. Knudsen Burette, an apparatus for the determination of salinity of water samples.

Figure 51. The Knudsen Burette, introduced by its inventor at the first international conference for the exploration of the sea in 1899, became one of the most used instruments in the world for determining salinity of a water sample.

Figure 52. Richter burettes, fabricated by Carl Richter at an indeterminate date. It is certain that the firm of Richter and Wiese made this type of burette for measuring salinity up until the recent times.

Figure 53. Schmidt burette - although little information exists regarding this instrument, it probably was invented by the German chemist Paul Schmidt for use on the VALDIVIA expedition in 1898-1899.

Figure 54. Pellet burette - this instrument was produced by the French chemist Henri Pellet. It uses the same principle as that of the Richter or Schmidt burette. It has an automatic zero level, in which the reactive reservoir is pressurized by a rubber bulb.

Figure 55. Boutron and Boudet hydrometric devices for measuring density of fresh water.

Plate 5. Knudsen apparatus for the determination of the nitrogen and oxygen levels in sea water. Model with three burettes.

Figure 56. Jacobsen device for extracting gases from sea water. This device was invented by Professor Oscar Georg Jacobsen, a member of the German Baltic expedition of 1871-1872. It was based on an instrument conceived by Robert Bunsen. Water samples were obtained by Meyer bottle.

Figure 57. Dittmar device for extracting gases from sea water. This device was described by the British professor William Dittmar of Anderson's College in Glasgow. He used it to analyze sea water sampled during the CHALLENGER expedition. It complemented the use of the Jacobsen apparatus used by John Y. Buchanan during the CHALLENGER expedition.

Figure 58. Classen device for the measurement of carbon dioxide in sea water. The German chemist Alexander Classen elaborated on the use of this device in 1876. The work of Wilhelm Borchers in 1878 on the determination of carbonic acid in mineral water that led to the use of this instrument. After improvement , it was used by Hercules Tornoe on the Norwegian North Atlantic expedition.

Figure 59. Dittmar device for measuring carbon dioxide in sea water. This device was used by William Dittmar, then professor at Anderson's College in Glasgow for analyzing sea water collected by the CHALLENGER expedition. This instrument is a variant of the apparatus designed by Alexander Classen and used by Hercules Tornoe on the Norwegian North Atlantic Expedition.

Figure 60. Regnard apparatus for the study of the diffusion of oxygen in sea water. Concerned with the diffusion of air in sea water in still water, Doctor Paul Regnard, a French physiologist, invented this device based on an experiment by Julien Thoulet. He used the property that certain materials change their color in the presence of oxygen and described the device in 1891.

Figure 61. Pettersson device for the measurement of oxygen and nitrogen in sea water. This device was developed by Professor Otto Pettersson who used it at the Hydrographic Station at Borno, Sweden. With this apparatus one could measure the oxygen, nitrogren, and carbon dioxide content of sea water. This instrument was first described in 1891.

Figure 62. Knudsen apparatus for the measurement of oxygen and nitrogen in sea water. This was a "multiple use" device that simultaneously was able to analyze sea water for the presence and amount of a number of gases. It was developed by the Dane Martin Knudsen and used by Ingolf in 1895 and 1896.

Figure 63. Sorensen device for the determination of H+ ions. This device which measured the pH of water by a colorimetric method was devised by the Danish chemists Soren Peter Lauritz Sorensen and Sven Palitsch and used during the Danish oceanographic expedition on the THOR between 1908 and 1910.

Plate 6. Thoulet device for separating minerals by means of an iodine solution. This device is typical of many that Julien Thoulet, a French mining engineer, developed for the study of sediments in the ocean. Thoulet became associated with the University of Nancy and then devoted himself to oceanography beginning in 1885.

Figure 64. Series of Thoulet's sieves for sorting sediment material of varying sizes on the top. On the bottom, various types of laboratory glass ware used by Thoulet in sediment studies. Thoulet was very concerned with the classificatio n of marine sediments beginning with his first interest in oceanography in 1885.

Figure 65. Thoulet device for separating sediment from water. This device was developed to obtain very fine sediment samples that were still suspended in the water after passing through a series of sieves. Thoulet developed this instrument in 1878 prior to developing an interest in oceanography.

Figure 66. Thoulet vertical tube for sorting sediments. According to Julien Thoulet, this device was "frequently used for the mechanical analysis of seafloor sediments being examined."

Figure 67. Pelometer for the rapid sorting of sediments in water. Professor Julien Thoulet used this device on board research ships to rapidly determine the nature of seafloor sediments. It would allow quick classification into a single category such as mud, sandy silt, or muddy sand for entry into a station log. Thoulet used the pelometer described by Bouquet de la Gyre.

Figure 68. Thoulet device for classifying minerals by means of an iodine solution. This device used the principle of buoyancy of solids in liquids to determine the density of the solid being tested. In this manner, mineral material in a bottom sample could be quickly determined.

Figure 69. Magnetic device for separating and classifying minerals. This early device that used an electro-magnet to separate minerals of different magnetic properties was conceived of by the French mineralogist Ferdinand Foque in 1879.

Figure 70. Thoulet device for measuring the density of minerals by means of an iodine solution. The method used in image ship4445 was very crude but this device gave a real measurement, which although a long and delicate process, could be very precise.

Figure 71. A Mohr-Westphal density balance. This instrument was first described in 1832 by the German chemist Carl Friedrich Mohr. It is a balance with two arms, where the equilibrium is reached by adding weight on a tray. This type of instrument was modified by G. Westphal who replaced the tray with an adjustable counterweight. Julien Thoulet used this type of instrument in his studies.

Figure 72. Pycnometers for the measurement of the density of sediments. According to Thoulet, the apparent density of a sediment is the weight per cm cubed of the dry sediment when compressed as much as possible. The true densit y is the relation of the weight of the sample relative to the weight of an equal volume of distilled water at 4C. Thoulet studied these sediment properties.

Figure 73. Thoulet device for measuring the virtual density of large samples. Julien Thoulet described this method in 1905 for determining the apparent density of pumice stones, in order to better understand the origin of these rocks which were found in abundance in bottom samples obtained by the PRINCESSE ALICE.

Figure 74. Device for determining the amount of carbon dioxide in a water sampl e. This is a Schoedter apparatus which is still used today. A sample is treate d with hydrochloric acid which transforms carbonates into chlorides at which time carbon dioxide is released. The difference in weight of a before and after sample determines the weight of CO2.

Figure 75. Device for determining the color of bottom samples. This device was conceived and described by Julien Thoulet in 1910.

Catalog of the Oceanographic Equipment in the Collection of the Oceanographic Museum at Monaco. 8. "Supplements, Demonstration Material, Meteorology: Additions and Cumulative Index, " by Christian Carpine. Bulletin of the Institute of Oceanography. Volume 76, 1999, No. 1444.

Figure 1. A plastic Secchi disk of recent origin. This disk is lowered in the water until it disappears from sight. The depth at which it disappears is a measure of the water's transparency. Father Angelo Secchi devised this method in 1865 and tested it aboard the Vatican vessel IMMACOLATA CONCEZIONE. Several models were tested of different colors.

Figure 2. A model of the vessel and equipment used by the French physiologist Paul Regnard for studies of light penetration in the water and its effects on chemical and biological phenomena. In 1889 and 1890, he performed several studies aboard a tartane, a small local fishing and trading vessel.

Figure 3. Brouardel's luxmeter. This instrument was constructed in 1956 at the Oceanographic Museum of Monaco by Jean Brouardel and Emile Rinck for their studies on the primary production in the Mediterranean Sea according to the methods of Steeman Nielsen. It was especially designed for photoelectric measurements in deep ocean water.

Figure 4. Li-Cor photometer. This photometer was investigated by Dr. Jean Brouardel in 1974 in a quest for instruments of greater precision. He investigated several including a Li-Cor quantum/radiometer/photometer developed by industry especially for measuring light in water or in air in relation to photosynthesis. Construction date and details of study conditions are unknown.

Figure 5. Compact luxmeter, used for study of light in air. Simplicity of design and use have joined with greater and greater precision of measurement in this mass-produced industry instrument. Although apparently an instrument used in meteorology, it is shown here because of the relationship between solar radiation and photo synthesis.

Figure 6. Pyranometer, a sensor used to measure variations in solar radiation. It is used with a recording device, the solarigraph. The principle of operation of the pyranometer is that of the thermophile of the Dutch Willem Moll. This principle was adapted by Dr. Ladislaw Gorczynski of the Meteorological Institute of Varsovia in 1924. The instrument shown was probably made in the 1940's.