A Treatise on Land-Surveying: comprising the Theory developed from five elementary principles; and the Practice with the chain alone, the compass...: Illustrated by 400 engravings & a magnetic chartD. Appleton and Company, 1859 - 418 pàgines |
Altres edicions - Mostra-ho tot
A Treatise on Land-surveying: Comprising the Theory Developed from Five ... William Mitchell Gillespie Visualització completa - 1881 |
A Treatise on Land-surveying: Comprising the Theory Developed from Five ... William Mitchell Gillespie Visualització completa - 1883 |
A Treatise on Land-surveying: Comprising the Theory Developed from Five ... William Mitchell Gillespie Visualització completa - 1875 |
Frases i termes més freqüents
ABCD acres alidade base line Bearing calculated centre CHAPTER chord circle compass complete quadrilateral convenient corner correct course cross-hairs desired desired line determined diagonal difference direction distance divided division Double Longitude draw drawn East equal error feet field Field-notes figure fixed gamboge given line given point half horizontal inaccessible inch instrument intersection Latitudes and Departures length line of sight MAGNETIC BEARING marked measured Meridian method needle object observed obtained offsets paper parallel pass perpendicular plane plat plate plumb-line preceding precisely prolonged protractor quadrilateral radius reading represent right angles scale screws side similar triangles sine South square chains stake station straight line subtract survey surveyor Table tangent telescope Theodolite Theorem tion township Transit trapezoid Trigonometry true North turn Variation Vernier Vernier scale vertical West whence
Passatges populars
Pàgina 153 - All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides.
Pàgina 365 - ... And in all cases where the exterior lines of the townships, thus to be subdivided into sections or half sections, shall exceed or shall not extend six miles, the excess or deficiency shall be specially noted, and added to or deducted from the western and northern ranges of sections or half sections in such township, according as the error may be in. running the lines from east to west, or from south to north.
Pàgina 372 - After a true coursing and most exact measurements, the corner boundary is the consummation of the work for which all the previous pains and expenditure have been incurred. A boundary corner in a timbered country is to be a tree, if one be found at the precise spot; and if not, a. post is to be planted thereat, and the position of the corner post is to be indicated by trees adjacent (called...
Pàgina 98 - Fig. 88. 40 links along the line. Let one assistant hold one end of the chain at that point ; let a second hold the 20 link mark which is nearest the other end, at the given point A., and let a third take the 50 link mark, and tighten the chain, drawing equally on both portions of it.
Pàgina 372 - The precise relative position of islands, in a township made fractional by the river in which the same are situated, is to be determined trigonometrically — sighting to a flag or other fixed object on the island, from a special and carefully measured base line, connected with the surveyed lines, on or near the river bank, you are to form connection between the meander corners on the river to points corresponding thereto, in direct line, on the bank of the island, and there establish the proper...
Pàgina 155 - Begin at the meeting of two or more of the principal streets, through which you can have the longest prospects. Having fixed the instrument at that point, and taken the bearings of all the streets issuing from it, measure all these lines with the chain, taking offsets to all the corners of streets, lanes, bendings, or windings ; and to all remarkable objects, as churches, markets, public buildings, &c.
Pàgina 372 - A sufficient number of other trees standing within 50 links of the line, on either side of it, are to be blazed on two sides diagonally, or quartering toward the line, in order to render the line conspicuous, and readily to be traced, the blazes to be opposite each other, coinciding in direction with the line where the trees stand very near it, and to approach nearer each other the farther the line passes from the blazed trees. Due care must ever be taken to have the lines so well marked as to be...
Pàgina 174 - When the bearing ia over 45°, the names of the columns must be read from the bottom of the page, the latitude of any bearing, as 50°, being the departure of the complement of this bearing, or 40°, and the departure of 40° being the latitude of 50°, etc.
Pàgina 44 - Multiply the sum of the parallel sides by the perpendicular distance between them, and half the product will be the area.
Pàgina 252 - This probable error is equal to the square root of the sum of the squares of the errors (ie the differences of each observation from the mean) divided by the number of observations, and multiplied by the decimal 0.674489. The same result would be obtained by using what is called " The weight" of the observation. It is equal to the square of the number of observations divided by twice the sum of the squares of the errors. The " Probable error" is equal to 0.476936 divided by the square root of the...