Compass, mariner

Iron oxides have played their part in navigation. Around the first millenium AD, magnetite, in the form of lodestone, was used in the earliest, crude mariners compasses. These enabled more difficult voyages to be undertaken and thus contributed to a furthering of trade and exploration. 

During the later centuries the power of the lodestone grew apace. Mountains of it beneath the sea could draw the very nails out of the ships sailing above them so that they fell to pieces even in calm weather. Similarly their presence would disturb the compass and lead the mariner astray. 

Sound navigation and ranging system (SONIA) record, Arabian Sea, day tectonics with considerable deformation. Distance between A-B is approximating 1600 m, C is a possible small gas seep, W-E compass directions for orientation. (Data from Van Overeem, A.J.A., Marine Geotech., 3,61-84,1978.)... 

Instrumented tripods with flowmeters, transmissiometers, optical backscatter sensors (OBS), in situ settling cylinders, and programmable camera systems have often been used in marine environments, for example, oceanographic studies of flow conditions and suspended particle movements in the bottom nepheloid layer [37,38]. These instruments were deployed to study suspended-sediment dynamics in the benthic boundary layer and were able to collect small water samples (1-2 L) at given distances from the seafloor. An instrumented tripod system (Bioprobe), which collects water samples and time-series data on physical and geological parameters within the benthic layer in the deep sea at a maximum depth of 4000 m, has been described [39]. For biogeochemical studies, four water samples of 15 L each can be collected between 5 and 60 cm above the seafloor. Bioprobe contains three thermistor flowmeters, three temperature sensors, a transmissiometer, a compass with current direction indicator, and a bottom camera system. 

Kelvin, Baron of Larges (Lord Thompson Williams) (1824-1907) Scot, math., did important contribution in most branches of physical science, developed dynamic theory of heat, collaborated in investigating Joule-Thompson effect, propose absolute scale of tempieratures, invented various electric measuring devices and even developed improved mariner s compass still used today Kemp Richard Bernard (1941-) Brit, zoolog., biothermochemical studies and... 

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