HIDDEN PERILS OF THE DEEP 



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THE BROOKLYN ROCK IN BUZZARDS BAY, MASSACHUSETTS 



Hundreds of soundings were made in the vicinity of this small rock, and yet its presence 

 was never discovered until the cruiser Brooklyn struck it in 1902. (This diagram is a portion 

 of the original hydrographic sheet). 



and 640 feet in 1903. The number of 

 vessels drawing as much as 26^ feet 

 rose from 36 in 1902 to 185 in 1904. In 

 1906 there were 17 vessels afloat drawing 

 32 feet and upward. There are now two 

 steamers on the Atlantic 790 feet long, 88 

 feet beam, and 37^ feet draft when fully 

 loaded, and two vessels with a length of 

 about 860 feet are under construction. 



THE ROCK ON WHICH THE BROOKLYN 

 STRUCK 



Good and reliable charts can be made 

 only from correct surveys. It is said that 

 men are apt to believe anything they see 

 on a map. As to the nautical chart, the 

 mariner is apt to be somewhat more crit- 

 ical, however, and it is well that he is. 

 There is great difficulty in charting thor- 

 oughly an invisible surface, such as the 

 bottom of the sea, and but a small part 

 of the navigable waters is surveyed in 

 sufficient detail to be certain of the ab- 

 sence of dangers. 



It is obvious that the plan of mapping 

 the sea bottom by dropping a lead at in- 



tervals over its hidden surface is far from 

 an ideal one. The lead gives the depth 

 only at the point at which it touches the 

 bottom, and no information as to the 

 space between the casts except such as 

 may be inferred from the relation of suc- 

 cessive soundings. In numerous cases, 

 after what was considered a thorough 

 survey of a region had been made, at 

 some later day a pinnacle rock or other 

 danger has been discovered. For in- 

 stance, a detailed hydrographic survey 

 of Buzzards Bay was made in 1895 ; the 

 sounding lines were run at intervals of 

 50 to 100 yards, and 91,000 soundings 

 were made for a single sheet. Within 

 this area the cruiser Brooklyn in 1902 

 struck a rock which was found to have 

 18 feet over it. (See diagram.) The 

 least depth in the vicinity developed in 

 the original survey was 31 feet. 



In 1902 a rock with 2j feet over it, 

 surrounded by depths of 50 feet, was 

 located in the North River, New York 

 Harbor, lying about 400 yards off the 

 Battery, in a position such that vessels 



