The Practical Navigator, and Seaman's New Daily Assistant: Being an Epitome of Navigation: Including the Different Methods of Working the Lunar Observations. With Every Particular Requisite for Keeping a Complete Journal at Sea ... To this Edition are Added ... the Requisite Tables Used with the Nautical Almanac in Determining the Longitude at Sea ... |
From inside the book
Results 1-5 of 91
Page 3
... half a Semi - circle . A Chord Line is a Right Line that cuts the Circle in two un- equal Parts called Segments . A Sector is a Figure included between two Radius's , and is lefs than a Quadrant . All Plan Triangles are Figures ...
... half a Semi - circle . A Chord Line is a Right Line that cuts the Circle in two un- equal Parts called Segments . A Sector is a Figure included between two Radius's , and is lefs than a Quadrant . All Plan Triangles are Figures ...
Page 5
... Half the given Line A B ) and one Foot of the Compaffes on A , defcrible the Arch C D ; with the fame Distance and one Foot on B , cross the former A Arch in C and D ; by C and D draw a Line , and that will cut A B in E the Middle , as ...
... Half the given Line A B ) and one Foot of the Compaffes on A , defcrible the Arch C D ; with the fame Distance and one Foot on B , cross the former A Arch in C and D ; by C and D draw a Line , and that will cut A B in E the Middle , as ...
Page 11
... Half the Chord of twice the Arch ; fo that RS is the Sine of the Arch S A , and of the Arch SD , the Sum of which Arches make 180 ° , or a Semi - circle . III . The verfed Sine is that Part of the Dia- meter contained be- Secant B Co ...
... Half the Chord of twice the Arch ; fo that RS is the Sine of the Arch S A , and of the Arch SD , the Sum of which Arches make 180 ° , or a Semi - circle . III . The verfed Sine is that Part of the Dia- meter contained be- Secant B Co ...
Page 34
... half their Difference . Which half Difference , being added to half the Sum of the Angles , gives the greater , but if fubtracted , the Remainder will be the leffer Angle . ** G * Produce the leffer Leg C B of the Tri- angle A B C ...
... half their Difference . Which half Difference , being added to half the Sum of the Angles , gives the greater , but if fubtracted , the Remainder will be the leffer Angle . ** G * Produce the leffer Leg C B of the Tri- angle A B C ...
Page 35
... half the Difference of the oppofite Angles :) but the Segments of the Legs of any Triangle cut by Lines parallel to the Bafe being ( by Eucl . 2. 6. ) proportional as F CĆ B :: FA : FG , that is , half the Sum of the Legs is to half ...
... half the Difference of the oppofite Angles :) but the Segments of the Legs of any Triangle cut by Lines parallel to the Bafe being ( by Eucl . 2. 6. ) proportional as F CĆ B :: FA : FG , that is , half the Sum of the Legs is to half ...
Common terms and phrases
againſt alfo Altitude Anchor Angle Arch Azimuth Bafe becauſe Cafe Cape Chart Co-fecant Co-fine Co-tang Coaft Column Compafs Courfe Courſe Declination Degrees Diff Difference of Latitude Difference of Longitude Dift Dep Dift Lat ditto Eaft Epact Equator Extent will reach fails fame Fathoms fecond fhews fhould find the Courſe find the Difference firft firſt fome ftands fteer fubtract fuch Funchal half haul High Water Hour Angle Hours Ifland laft Latitude and Departure lefs Line of Numbers Line of Sines Logarithm Long meaſured Mercator's Sailing Merid Meridian Meridian Altitude Middle Latitude Miles Moon Moon's muſt N.fine neareſt Noon North Obfervation oppofite Parallax parallel Place Plane Sailing Point Radius Rifing Right Afcenfion Secant ſhe Ship Ship's Side South Star Star's Sun's Suppofe Table Tangent thefe theſe thofe uſed Variation Weft Wefterly Wind ΙΟ
Popular passages
Page 19 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees ; and each degree into 60 equal parts, called minutes ; and each minute into 60 equal parts, called seconds ; and these into thirds, etc.
Page 14 - EXAMPLE. If the diameter of a circle be 7 inches, and the circumference 22, what is the circumference of another circle, the diameter of which is 14 inches ? Extend from 7 to 22, that extent will reach from 14 to 44 the same way.
Page 32 - ... the sum of the segments of the base is to the sum of the sides as the difference of the sides to the difference of the segments of the base.
Page 14 - All fractions found in this line must be decimals ; and if they are not, they must be reduced into decimals, which is easily done by extending the compasses from the denominator to the numerator; that extent laid the same way, from 1 in the middle or right hand, will reach to the decimal required.
Page 263 - A figurative expression for the timbers. /fuie at anchor, is when a ship is held by her anchors, and is not driven by wind or tide. To ride athwart, is to ride with the ship's side to the tide. To ride hoirie fallen, is •when the water breaks into the hawse in a rough sea.
Page 151 - Complement of the Latitude Is to Radius, So is the Sine of the Sun or Star's Declination To the Sine of the true Amplitude ; Which is always of the fame Name with the Declination, whether North or South.
Page 120 - The most usual way of discovering the set and drift of an unknown current, is thus : Let three or four men take a boat a little way from the ship : and by a rope fastened to the boat's stern, let down a heavy iron pot or loaded kettle to the depth of 80 or 100 fathoms ; then heave the log, and the number of knots run out in half a minute will be the miles the current sets per hour, and the bearing of the log will show the set of it.
Page 14 - The solid content of any bale, box, chest, fcc. is found by extending from 1 to the breadth ; that extent will reach from the depth to a fourth number, and the extent from 1 to that fourth number will reach from the length to the solid content.
Page 205 - PM per watch, the altitude of the sun's lower limb was 28° 20' above the horizon of the sea, the eye being elevated 20 feet above the surface of the water, and the sun's bearing by compass S. by W. and at 2h. 58m. 2Gs. PM by watch, the altitude of the sun's lower limb was 16° 41...
Page 164 - A ship lying-to under her mainsail, with her starboard tacks aboard, comes up E. by S. and falls off NE by E. there being one point westerly variation, and she makes 5 points lee-way — what course does she make good ? The middle between E. by S. and NE by E. is E. by N. ; and by allowing 6 points to the left hand (viz.