The American Practical Navigator; Being an Epitome of Navigation and Nautical Astronomy

The American Practical Navigator; Being an Epitome of Navigation and Nautical Astronomy

By (author) 

List price: US$15.82

Currently unavailable

Add to wishlist

AbeBooks may have this title (opens in new window).

Try AbeBooks


This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1888 edition. Excerpt: ...Reports of i854-'55-'56-'57, l86i-'62, and to Navy Scientific Paper No. 2, 1868, by Henry Mitchell, Assistant United Stales Coast Survey, on Tides and Tidal Phenomena. Art. 363. Tidal phenomena present themselves to the observer under two aspects: as alternate elevations and depressions of the sea, and as recurrent inflows and outflows of streams. The word tide, in common usage, is applied without distinction to both the vertical and the horizontal motion of the sea, and much confusion has arisen among navigators from this double application of the term. Careful writers of modern times, however, use the word tide in strict reference to the changes of elevation, while they distinguish the recurrent stieams as tidal currents or tidal drifts. The words rise and fait should be used in referring to the tide, and the words flood and ebb in referring to the tidal current. The word stand should be used specifically for the period of time, at high or low water, when no vertical change can be detected, and the word slack for the period of time when no horizontal motion can be detected. Set and drift are terms applicable only to the tidal currents, the first for direction and the second for velocity. The range of the tide is the height from low water to high water. This term is usually applied to the average height; but upon the Coast Survey Chart the expression mean rise and fall replaces it. Art. 364. The cause of the tides is the unequal attraction of the sun and moon upon different parts of the earth; for they attract the parts of the earth's surface nearer to them with a greater force than they 00 its centre, and attract the centre more than they do the opposite surface. To restore the equilibrium the waters take a spheroidal figure, more

Product details

  • Paperback | 242 pages
  • 189 x 246 x 13mm | 440g
  • United States
  • English
  • black & white illustrations
  • 123680726X
  • 9781236807267