An Introduction to Geodetic Surveying; In Three Parts I. the Figure of the Earth. II. the Principles of Least Squares. III. the Field Work of Triangu
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1892 edition. Excerpt: ...normal to the geoid. The differences of these two, as noted in the last column, are the 4 same as the angles between the two normals, and indicate the relative plumb-line deflections at the stations. The above figure shows on a small scale the general trend of the coast, the position of the latitude stations and the meridian arc. It might, perhaps, be expected in advance that the actual directions of the plumb lines at these points would deviate northwestwardly from the normals to a spheroid for two reasons; first, because of the heavier continent lying north and west, and secondly, because of the lighter waters lying south and east. To judge concerning this, let us imagine a section of the earth and the spheroid and the geoid along the meridian arc. Let F be a point on this meridian having the same latitude as Farmington, S a point having the same latitude as Sebattis, and similarly for the other stations, and let us consider that the plumb-line directions at these points are the same as at the latitude stations themselves, as far at least as north and south deviations are concerned. Draw, as in the following figure 10, an arc of an ellipse FSIATMN to represent a section of the spheroid along the meridian arc, and let the distances FS, SI, etc., be laid off to scale equal to the distances as found from the base line and triangulation. (See paragraph 23.) Draw at these points normals to the ellipse; these will make with the earth's equator (to which QQ in the figure is drawn parallel) angles equal to the above geodetic latitudes. At F draw a line FZ making with QQ an angle equal to the observed astronomical latitude, so that SFX represents 2."25, the plumb-line deviation at F. Draw at each of the other points similar broken lines, each of...
- Paperback | 34 pages
- 189 x 246 x 2mm | 82g
- 29 Jun 2012
- Miami Fl, United States
- Illustrations, black and white