Work of the U. S. Hydrographic Office 67 



alone there are thousands of reported 

 dangers. Many of these are probably 

 either inaccurately located or do not 

 exist, but all the same they are a hin- 

 drance to navigation through the anx- 

 iety and loss of time which the fear of 

 their possible existence causes to ship- 

 masters. Fortunately, little by little the 

 national vessels of the Great Powers are 

 either accurately locating or disproving 

 the existence of many of these. I am 

 glad to say that our own naval vessels 

 have done their share in this good work. 



DEEP-SEA SOUNDINGS 



Our knowledge of the depths of the 

 sea is gradually increasing through the 

 operations of deep-sea sounding expedi- 

 tions undertaken by many nations. In 

 this field of operations we hold a com- 

 manding position. From a scientific 

 point of view, a knowledge of the phys- 

 ical characteristics of the ocean bed is 

 most desirable, and no less so from a 

 practical standpoint. No telegraph 

 company would think of laying a sub- 

 marine cable today without first select- 

 ing a desirable route as determined by 

 deep-sea soundings. The soundings of 

 the U. S. S. Nero in the Pacific two 

 years ago determined the route since 

 selected for the transpacific cable. 



Deep-sea soundings are also of espe- 

 cial value to the mariner, inasmuch as 

 from their results the existence of sub- 

 marine dangers is frequently indicated. 

 In the Atlantic the greatest accurately 

 known depth in the fifties was obtained 

 by the then Lieut. S. P. Lee, in the 

 U. S. brig Dolphin, 3,825 fathoms (4^ 

 miles) . Only a year ago the now great- 

 est known depth in the Atlantic, 4,662 

 fathoms (5^4 miles), was found by the 

 present U. S. S. Dolphin, the first ves- 

 sel of the new Navy. The greatest 

 known depth in the world is in the 

 Pacific, and is 5,269 fathoms (31,614 

 feet), 66 feet short of 6 statute miles. 

 This depth was obtained by the U. S. S. 

 Nero in 1900, and is greater than any 



elevation on our continent, or, as far as 

 we know, in the world. 



SAILING DIRECTIONS 



The Sailing Directions, to which I 

 have previously referred, can properly 

 be designated as nautical guide books — 

 in other words, nautical Baedeckers. 

 The coasts of the world are divided up 

 into numerous sections, for each one of 

 which a book of sailing directions is 

 prepared. Thus we have Sailing Di- 

 rections of the East Coast of South 

 America, etc. These seamen's guide 

 books, when complete and used in con- 

 nection with the corresponding naviga- 

 tional charts, are supposed to give the 

 mariner all the information that he may 

 require for safely navigating the part of 

 the world considered, and for entering 

 and leaving each harbor or anchorage 

 therein. When corrected to date, they 

 give him in as much detail as possible, a 

 knowledge of the prevailing winds and 

 weather for each season ; of the tides, 

 currents, buoys, lights, and other day 

 and night marks, and of proper anchor- 

 ages. In addition, where possible .ranges 

 to be used in entering and leaving port, 

 both by day and night, are described ; 

 prominent landmarks and other topo- 

 graphical features are noted in detail, 

 and everything in the way of an aid to 

 navigation is entered therein. They 

 even go so far as to give him infor- 

 mation in regard to port dues, local 

 regulations of foreign governments, 

 diplomatic customs of the local and 

 state authorities, the facilities for ob- 

 taining provisions, water, and other sup- 

 plies, and also as to obtaining necessary 

 repairs. 



There is no guide book known which 

 contains so much of practical impor- 

 tance. In all nations these books arewrit- 

 ten by naval officers or by others who 

 have followed the sea for a profession — 

 men who have had sufficiently matured 

 practical experience to enable them to 

 exercise proper judgment in weighing 



