Both ships have extensive laboratory space, winches for lowering 

 instruments on wires and electric cables, for mid-water trawling, 

 bottom dredging, sediment coring, and other heavy tasks which 

 are described later in this chapter. Because the scientific teams 

 usually change from cruise to cruise, much special apparatus has 

 to be installed and removed at the beginning and end of each 

 voyage. When the ship reaches a "station," a variety of work begins, 

 the scientists usually standing watches like the seamen. One task 

 may be to take samples of the water at different depths. To do this, 

 a series of water-sampling devices (with thermometers) are attached 

 to one of the wires and lowered until the bottom one is near the 

 sea bed. They are all tripped and closed by small "messenger" 

 weights that slide down the wire, each sampler releasing a similar 

 weight to operate the one below, so that they all close one after 

 another. Fine silk nets may be hauled vertically and towed horizon- 

 tally and obUquely to sample the plankton. Deep-sea cameras may 

 be lowered to the bottom, and different kinds of dredges used to 

 sample the bottom-living fauna, or to collect rock samples. Many 

 other observations are made as the ship steams along - temperature 

 recordings, echo-sounding profiles, wave records, records of total 

 magnetic and gravimetric field, and meteorological observations. 

 There is not much rest for anyone until the ship returns home. 

 Even then, each scientist usually spends many weeks or months 

 analyzing his findings. 



For centuries the depths of the oceans have puzzled men. Later 

 in this chapter Dr. Laughton tells of early speculations about the 

 ocean depths and shows that new moves to gather factual infor- 

 mation started in the eighteenth century. Count Luigi Marsigli, 

 the Italian soldier and scientist who published a Histoire Physique 

 de la Mer in 1725 wrote: "The fishermen working on that slope 

 where they are in the habit of finding coral at 1 50 and 200 fathoms, 

 and their lines not allowing soundings in greater depths, imagine 

 that the bottom cannot be found, and call it in their exaggerated 

 jargon a bottomless abyss, impossible to be sounded. This idea 

 entertained by people of experience in marine matters, as well as by 

 the simple fishers, appears to be absurd, and founded merely on the 

 fact that nobody has yet cared to undertake the trouble and expense 

 required for such soundings, which according to all appearances 

 will never be made unless some Prince orders for that purpose 

 special vessels with suitable instruments." 



It was indeed from a King's ship, H.M.S. Racehorse, that the first 

 deep sounding was made, and in two young Queen's ships H.M.S. 

 Erebus and Terror, that Sir James Clark Ross, as we saw in an earlier 

 chapter, made deep soundings all around the world. The next step 

 was made by Midshipman Brooke on the other side of the Atlantic 

 Ocean. One of Lieutenant Maury's assistants, he used a hollow 

 tube, a forerunner of modern core samplers, running through the 

 middle of the sounding weight (actually a cannon ball). There were 

 catches to release the ball as soon as it touched bottom. This made 

 recovery of the sounding Line much easier and allowed the use of 

 thinner lines. Soon after this, cable ships began to sound out routes 

 for submarine cables, and they used a wire sounding machine 

 developed by Lord Kelvin. In spite of these advances and increased 

 interest, the total number of deep-ocean soundings recorded by 

 19 1 4 was only about 6000. 



A water color by John Clevely shows H.M.S. 

 Racehorse in pack ice during her 1773 voyage 

 toward the North Pole. Commanded by C.J. 

 Phipps, she made the first deep-sea sounding 

 between Iceland and Norway. 



This relief map of the Atlantic Ocean shows 

 the most prominent features of the sea 

 floor. The mid-Atlantic Ridge runs almost 

 parallel to the coast of America on one side, 

 and to the coasts of Europe and Africa on 

 the other. There are side ridges which 

 divide the east and west basins, one of the 

 sharpest being the Walvis Ridge. The 

 Scotia arc which joins South America to 

 Graham Land is a prominent feature in the 

 south, and there is a deep trench east of 

 the South Sandwich Islands. The greatest 

 depth is 30,246 feet off Puerto Rico. 



177 



