Figure 30. Pendulum current meter invented by Fridtjof Nansen in 1901 with considerable improvements made in 1903. This instrument was not able to accurately measure weak currents.

Figure 31. Ekman current meter invented by V. Walfrid Ekman about 1903. This instrument was distinguished by its original manner for measuring both the strenth and direction of the current. It was very robust and used throughout the world during the first half of the 20th Century. It was first tested in the Skagerrak in 1903 aboard the MICHAEL SARS.

Figure 32. Ekman current meter as modified by Max Marx in 1913.

Figure 32 (continued). View of helical impeller of Ekman current meter as modified by Max Marx.

Figure 33. Clockwork counting device of Ekman current meter. Left: before triggering the release. Right: After triggering the release.

Figure 34. Universal current measuring device invented by Otto Petterson in 1904. This instrument was intended to measure current and temperature, as well as collect plankton. Left: in operation. Right: after measurement. This instrument was first tested in the Skagerrak and then in the Baltic Sea between 30 and 200 meters water depth.

Figure 35. Current meter invented by Giovanni Boccardo in 1906. Boccardo was the chief instrument maker of the Royal Italian Hydrographic Institute. This high precision instrument eliminated many of the faults of earlier current meters. It was first tested near La Spezia about 1906.

Figure 36. Current meter invented by Jacob Peter Jacobsen in 1909. Left: view of the assembled unit. Right from top to bottom: bubble levels; sample bucket. This instrument was used by Jacobsen for many years. He first tested it in the Grand Belt from the vessel THOR in 1909.

Figure 37. Current meter invented by Otto Pettersson 1910 with photographic recorder. Left: view of the assembled unit. Right: details of the measuring device and recorder. This was the first current measuring device to be able to record both direction and strength of current for long periods. It was first used from a pontoon at Goteborg in 1911.

Figure 38. Percussion current meter invented by Julien Thoulet. Top: Number 99 0610. Bottom: Number 99 0611. When the helix turned it caused a striker to fall on a steel plate. The sound of this was recorded by a hydrophone and the number of recorded sounds per unit time was directly related to current strength . This was tested off Monaco by Dr. Jules Richard in 1921.

Figure 39. Current indicator invented by James Norman Carruthers in 1924. This meter works on the principle used in the Robinson anenometer. Left: picture of the unit. Right: unit open to view interior mechanism. This current meter was meant primarily for use by fishermen. It was first tested off the fireboat SAINT NICHOLAS off Great Yarmouth, Great Britain, in 1924.

Figure 40. Current recording device invented by Pierre Idrac in 1927. This device was first used in the Gulf of Gascogne and in the la Manche on the vessel POURQUOI-PAS in 1927.

Figure 41. Current meter and recording device invented by Kohei Ono in 1950. Above: Picture of the unit. Below: the recording mechanism. This instrument was built by the Ogawa Seiki Company, Ltd., of Tokyo.

Figure 42. A BBT-Neyrpic current recorder made between 1950 and 1952 as the result of a collaboration between the companies of Barbier, Benard & Turenne and Nepyric. The official test of this instrument was in the Gulf of Sfax about 1951 in four meters of water. This instrument had higher precision and was more manageable than many of its predecessors, but abandoned photographic recording.

Figure 43. A Plessey current meter and recorder. Built by Plessey Electronics circa 1969. This instrument was conceived by the Christian Michelson Institute of Bergen, Norway, under the auspices of the undersea oceanographic committee of the North Atlantic Treaty Organization.

Figure 44. A buoy with a drogue used by the CHALLENGER Expedition in the Gulf Stream for current studies in 1873. The drogue acts like an underwater sail and is pushed by the current. The buoy allows visual tracking of the motion of the drogue. It was first tested off Bermuda in in 1873 in separate tests at 50 fathoms, 100 fathoms, and 600 fathoms.

Figure 45. A rheostat controlled bathymeter invented by Emil Stahlberger in 1873. This instrument was designed to measure currents, depth, and take bottom samples. It was used for the first time in the Gulf of Fiume aboard the Austrian corvette MINERVA.

Figure 46. Float built by Henry Mitchell of the U. S. Coast Survey in 1874 for use by C&GS Ship BLAKE in Gulf Stream studies.

Figure 47. Float devised by Prince Albert I of Monaco and Professor Georges Pouchet in 1885 and used on board l'HIRONDELLE in the same year to study currents of the North Atlantic Ocean.

Figure 48. Test float devised by Prince Albert I of Monaco and Georges Pouchet in 1887 to study currents. This float was never used in practice. This float was made by the instrument-maker E. Deriveau.

Figure 49. Float invented by Prince Albert I of Monaco and Georges Pouchet for study of currents in the North Atlantic off l'HIRONDELLE in 1887. Left: the unit as it would be seen in the water. Right: the internal structure of the float. A thousand of these floats were released mainly northwest of the Azores in July 1887.

Figure 50. Example of message included in floats invented by Prince Albert I of Monaco. Left: glass tube encasing the message. Right: Message as written in ten languages. The message requested information regarding the circumstances of of discovery of the float. This type of float was used between 1885 and 1887, but floats with this particular message were used in 1886

Figure 51. Coupled bottle floats devised by Alfred Hautreux in 1893 for the study of currents in the Gulf of Gascogne. These bottles were deployed from various naval vessels in 1893 and 1894.

Figure 52. Floats used by the Oceanographic Society of the Gulf of Gascogne in 1901 and deployed by the ship BRESIL. This work was done under instructions by Prince Albert I of Monaco.

Figure 52 (continued). Instructions to finders of the floats used by the Oceano graphic Society of the Gulf of Gascogne. These instructions were used by the packet boat CHILE in 1905.

Figure 52 (end). Instructions to finders of the floats used by the Oceanographi c Society of the Gulf of Gascogne. These instructions were used by the steamer l'ANDRE'E in 1906.

Figure 53. A bottom float for studying currents in closed basins of small extent used by the Copenhagen Hydrographic Laboratory. Left:float. Right: message. This float was first conceived by George P. Bidder with the aid of the Marine Biological Association of Plymouth, U. K., and first used from the HUXLEY in 1904 when 390 were launched in the North Sea.

Figure 54. A float used by the Oceanographic Society of San Sebastien and deployed from the vessel MAMELENA in 1911 in the vicinity of San Sebastien. Left: float device. Right: included message as written in Spanish, French, and English.

Figure 55. A coupled sinking float for use on the high sea devised by Julien Thoulet in 1896. This is the original model that was never tested at sea.

Catalog of Oceanographic Equipment Contained in the Collection of the Museum of Oceanography of Monaco. 3. "Biological sampling apparatus" by Christian Christian Carpine. Bulletin de l'Institute Oceanographique, Vol. 74, No. 1438. 1991.

Plate I. A Richard vertical net after return to the surface in 1908.

Figure 1. A Cori net, devised by the Austrian Carl Cori at the Trieste zoological station in 1899. This net was used for a variety of studies , primarily depending on the size of the mesh of the net. This net was first tested in the Adriatic near Trieste.

Figure 2. A large Cori bathypelagic net. Left: view of the net. Right: the biologic sample recovery unit. This unit was designed and built about the same time as the preceding net.

Figure 3. Petersen's net for young fish devised by C. G. Johan Petersen in 1902. Left: view of the net. Right: view of the connectors. This net was designed to capture the young of commercial species for further study. It was tested about 1902 at the Small Belt on board the SALLINGSUND, the ship of the Danish biological station

Figure 4. Biological sample recovery unit for use with Cepede net. Invented by Casimir Cepede at the Wimereux zoological station in 1907. The first test of this instrument was probably near Wimereux (in the vicinity of Dunkirk) at about the time of its invention.

Figure 5. The large Bouree bathypelagic net invented by Henry Bouree and used on the PRINCESS ALICE II in 1910. This vertical sampling net was tested in 1910 between the depths of 0 and 4900 meters off the coast of Spain. It was meant to capture pelagic animals from the greatest depths of the sea.

Figure 6. De Guerne bucket biologic sample recovery unit devised by Baron Jules De Guerne about 1893. a collaborator with Prince Albert I of Monaco. Use of this instrument depended on which type of net was used and how long the tow. It is almost certain that this instrument existed in this form by 1893.

Figure 7. Isaacs-Kidd trawling net for intermediate depths. Devised by John D. Isaacs and Lewis W. Kidd from Scripps Institution of Oceanography in 1950. above shows the net at the point of immersion. This net was meant to capture very large animals of very great speed. This net was successfully tested at more than 1000 meters water depth off California in 1950.

Figure 7 (continued.) Plan of the original model of the Isaacs-Kidd trawling net.

Figure 8. Plan of the original model of the WP3 trawling net as recommended by working group Number 3 of the Scientific Committee on Oceanic Research in 1966. This net was meant to capture large plankton. It was afterwards tested by several laboratories and found to have many shortcomings such as inefficienci es in capturing fish larvae and in the opening of its mouth.

Figure 9. Cone for use with Hensen conical net. Invented by Victor Hensen of the University of Kiel in about 1883. He called this invention " Korbnetz." In 1901 he described an improved version that contained a tin-plate envelope. Between these dates, an intermediate form of this net and cone was used in the course of the Plankton Expedition of 1889.

Figure 10. Cylinder for use with Hensen cylindrical surface-towed net at about the same time as the cone mentioned previously. This net, for qualitative collecting

Figure 11. Meter for use with Buchet plankton net, devised by Gaston Buchet in 1892. Left: front view. Right: side view. This instrument was designed to capture pelagic animals while being towed at a relatively high rate of speed. It was tested off Iceland in 1892 and also used in a number of expeditions of Prince Albert I of Monaco.

Figure 12. Borgert net devised by Dr. Adolph Borgert of Hamburg in 1893. Having found the Hensen and Buchet nets too heavy, too complicated, and difficult to manage, and too expensive, Dr. Borgert designed this net for collecting plankton at the surface at high speed. This net was first tested from the steamer BARCELONA between Hamburg and the western Mediterranean.

Figure 13. Richard narrow-ended net. Left: simple model. Right: model with deflector. Invented in 1903 by Doctor Jules Richard, this net combined extreme lightness with ease of making as well as a great facility for use by a ship underway. The prototype of this net was constructed on the PRINCESSE-ALICE II. Prince Albert I used this for thousands of plankton sampling tows from 1903 on.

Figure 14. Apstein plankton tube. Above: Top view. Below: bottom view. Invented by Carl Apstein who had been studying lake fauna. Apstein collaborated with Hensen to work in the Baltic and North Seas. Apstein perceived quickly that methods of work would have to vary considerably from lake work and made thi s instrument for collecting small plankton under difficult conditions.

Figure 15. Zacharias ethmophore plankton filter devised by Otto Zacharias in 1907. Top: view of the assembled apparatus. Bottom: internal speed reduction valve. This instrument was devised to collect plankton under adverse meteorolog ical conditions where normal net-towing operations became impossible. This inst rument was first used in a lake, but then in the Mediterranean and Tyrhennian.

Figure 16. Monti net tube devised by Madame Rina Monti of the University of Sassari in Sardinia. Top: the assembled unit. Middle: the internal net. Bottom: series of diaphrams used in the unit. This net and tube system were meant to improve shortcomings found in various other surface plankton sampling systems and was first tested off the coast of Sardinia in 1911.

Figure 17. Hyponeuston net for capturing life in the top 5 centimeters of the water column. This net was devised by Yuvenalii P. Zaitsev of the biological station at Odessa and meant to capture plankton from the very top of the water column. The top of the net was actually half out of the water when being towed while the bottom skimmed the surface. First made in 1959.

Figure 18. Net closure device invented by Baron Jules De Guerne and Paul Dumaig e and first tested in the east Atlantic in 1886 in 31 meters waters depth. Left: closed. Right: open.