Explorations and field-work of the Smithsonian Institution in .. . Fig. 13.—The dredge comes in with about a ton of soft, oozy mud composedof the minute skeletons of marine Fig. 14.—A Chesapeake Bay oyster dredge was found to be a useful tool onrough bottom, where the chain links of the bag prevented tearing. 12 SMITHSONIAN INSTITUTION farthest parallel was also run, with a similar interval. The threeparallel lines were 20 miles apart, and the deepest sounding recorded,using a 400-fathom per second standard, was 4,400 fathoms. Thisii-second interval was twice recorded. It should he s
Explorations and field-work of the Smithsonian Institution in .. . Fig. 13.—The dredge comes in with about a ton of soft, oozy mud composedof the minute skeletons of marine Fig. 14.—A Chesapeake Bay oyster dredge was found to be a useful tool onrough bottom, where the chain links of the bag prevented tearing. 12 SMITHSONIAN INSTITUTION farthest parallel was also run, with a similar interval. The threeparallel lines were 20 miles apart, and the deepest sounding recorded,using a 400-fathom per second standard, was 4,400 fathoms. Thisii-second interval was twice recorded. It should he stated that thedepth here provisionally recorded will eventually he considerablyhigher—more than fathoms—when corrections for salinity andtemperature have been applied. In addition to these soundings, manyreadings were taken before and during dredging operations. We alsocarefully sounded out a 5-mile square in i\Iona Island passage in orderto learn the contour of the bottom and shape our dredging activitiesaccordingly on this exceedingly rough bottom. The speed with whichrecords of this kind can now be accurately obtained makes sonicsounding a vast improvement over
Size: 2262px × 1105px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectscienti, bookyear1912
