Elements of Surveying, and Navigation: With Descriptions of the Instruments and the Necessary TablesA. S. Barnes & Company, 1854 - 322 páginas |
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Página 81
... sights mark some distinct object ; then look through the other sights , and place a staff on the line which they indicate : let the cross be then turned until the sights of the bar AB come to the same line : if the other sights are ...
... sights mark some distinct object ; then look through the other sights , and place a staff on the line which they indicate : let the cross be then turned until the sights of the bar AB come to the same line : if the other sights are ...
Página 84
... sight to the object D , and let the E B point , at which the line AD cuts the staff BE , be marked . Measure the distance BE on the staff ; then , AB : BE :: AC CD , whence CD becomes known . If the line AC cannot be measured , on ...
... sight to the object D , and let the E B point , at which the line AD cuts the staff BE , be marked . Measure the distance BE on the staff ; then , AB : BE :: AC CD , whence CD becomes known . If the line AC cannot be measured , on ...
Página 98
... sight there is a large and small aperture or slit ; the larger aperture being above the smaller in one of the sights , and below it in the other . A hair or thread of silk is drawn vertically through the middle of the large aperture ...
... sight there is a large and small aperture or slit ; the larger aperture being above the smaller in one of the sights , and below it in the other . A hair or thread of silk is drawn vertically through the middle of the large aperture ...
Página 99
... sights AF and BG . To effect this , a small arc HI is described on the bar AB , having its centre at the centre of the compass - box . This arc is divided to degrees , and sometimes to the parts of a degree . A vernier is also used ...
... sights AF and BG . To effect this , a small arc HI is described on the bar AB , having its centre at the centre of the compass - box . This arc is divided to degrees , and sometimes to the parts of a degree . A vernier is also used ...
Página 101
... sight , or reverse bearing . 8. The perpendicular distance between the east and west lines drawn through the extremities of a course , is called the northing or southing , according as the course is run to- wards the north or south ...
... sight , or reverse bearing . 8. The perpendicular distance between the east and west lines drawn through the extremities of a course , is called the northing or southing , according as the course is run to- wards the north or south ...
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Términos y frases comunes
axis back-sight base line bearing called centre column comp Cosine Cosine D course decimal degrees determined diff difference of latitude difference of level direction divided double meridian distance draw east error example feet figure fore-sight given angle given line given point half hence horizontal distance horizontal line hypothenuse inch instrument intersection LatDegDegDegDeg length limb line of collimation logarithm longitude M.
M. Sine marked measure method middle latitude miles multiplied paper parallel PARALLEL SAILING perpendicular plane of reference plane sailing plane triangle protractor quotient radius right angles right-angled triangle rods sailing scale of chords scale of equal screws secant sector sides sights Sine Cotang Sine D spherical excess spider's lines square chains staff station straight line subtract surface survey Tang tangent telescope theodolite trigonometrical vernier plate vertical yards
Pasajes populares
Página 14 - The logarithm of the quotient of two numbers is equal to the logarithm of the dividend minus the logarithm of the divisor.
Página 42 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees...
Página 13 - The logarithm of a number is the exponent of the power to which it is necessary to raise a fixed number, in order to produce the first number.
Página 25 - ... 20. An EQUILATERAL polygon is one which has all its sides equal; an equiangular polygon, is one which has all its angles equal. 21. Two polygons are mutually equilateral, when they have their sides equal each to each, and placed in the same order : that is to say, when following their bounding lines in the same direction, the first side of the one is equal to the first side of the other, the second to the second, the third to the third, and so on. 22. Two polygons are mutually equiangular, when...
Página 20 - The difference of the logarithms, as here used, means the algebraic difference ; so that, if the logarithm of the divisor have a negative characteristic, its sign must be changed to positive, after diminishing it by the unit, if any, carried in the subtraction from the decimal part of the logarithm.
Página 135 - Soon after the organization of the present government, several of the states ceded to the United States large tracts of wild land, and these together with the lands since acquired by treaty and purchase, constitute what is called the public lands or public domain. Previous to the year 1802 these lands were parcelled out without reference to any general plan, in consequence of which the titles often conflicted with each other, and in many cases, several grants .covered the same premises. In the year...
Página 96 - Then, find the areas of the triangles separately, and their sum will be the area of the quadrilateral.
Página 43 - The tangent of an arc is the line which touches it at one extremity, and is limited by a line drawn through the other extremity and the centre of the circle. Thus, AC is the tangent of the arc AB.
Página 28 - B + 0, the product would be indicated thus; (A+D)x(A-B+C), whatever is enclosed within the curved lines, being considered as a single quantity. The same thing may also be indicated by a bar : thus, A+B+OXD, denotes that the sum of A, B and C, is to be multiplied by D.
Página 1 - The minutes in the left.hand column of each page, increasing downwards, belong to the degrees at the top ; and those increasing upwards, in the right.hand column, belong to the degrees below.