The New American Practical Navigator: Being an Epitome of Navigation; Containing All the Tables Necessary to be Used with the Nautical Almanac, in Determining the Latitude, and Longitude by Lunar Observations ...
E.M. Blunt, 1826 - 617 sider
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added altitude anchor angle apparent applied arch bearing calculation called Cape central centre circle co-sec co-sine column compass correction corresponding course declination Degs departure Diff difference of latitude direction Dist distance divided draw east elapsed equal equator error EXAMPLE extent feet given gives glass greater Greenwich half head horizon Island less limb logarithm Long longitude lower manner marked mean measured meridian method middle miles minutes moon moon's Nautical Almanac nearly noon object observation obtained opposite parallax parallel passing plane radius refraction rule sails secant ship ship's Shoal side sine ſº star subtracted sun's supposed Table taken tangent true variation watch wind zenith
Side 10 - The angle in a semicircle is a right angle ; the angle in a segment greater than a semicircle is less than a right angle ; and the angle in a segment less than a semicircle is greater than a right angle.
Side 195 - If the vessel be double-decked, take the length thereof from the fore part of the main stem, to the after part of the stern post, above the upper deck"; the breadth thereof at the broadest part above the main wales...
Side 30 - To find the logarithm of a vulgar fraction. RULE. Subtract the logarithm of the denominator from the logarithm of the numerator...
Side 248 - Sear up, or bear away, is to change the course of a ship, in order to make her run before the wind...
Side 15 - TO THEIR DIFFERENCE ; So IS THE TANGENT OF HALF THE SUM OF THE OPPOSITE ANGLES', To THE TANGENT OF HALF THEIR DIFFERENCE.
Side 211 - 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 nearest to them, with a greater force than they do its centre : and attract the centre more than they do the opposite surface. To restore this equilibrium the waters take a spheroidal figure, whose longer axis is directed towards the attracting luminary.
Side 195 - ... take the depth from the under side of the deck plank to the ceiling in the hold, then multiply and divide as aforesaid, and the quotient shall be deemed the tonnage.
Side 6 - CO-SINE of an arch is the sine of the complement of that arch, or of what that arch wants of a quadrant ; thus AH being a quadrant, the arch SH is the complement of the arch AS ; SZ is the sine of the arch SH, or the co-sine of the arch AS. XXI. The VERSED SINE of an arch is that part of the diameter...
Side 93 - The index and horizon glasses must be perpendicular to the plane of the instrument, and their planes parallel to each other, when the index division of the vernier is at 0° on the arc ; and the optical axis of the telescope must be parallel to the plane of the instrument. We shall speak separately of each of these adjustments.