 | Geological Survey (U.S.) - 1889 - 1236 pages
...SUBFACE. (6). An expression for the area of a zone of the earth's surface or of a quadrilateral bounded by meridians and parallels may be found in the following...: The area of an elementary zone dZ, whose middle latitude is <p and whose width is pm dip, is (see FIG. 1), dZ=2-r ¡>m d<p By means of the relations... | |
 | Smithsonian Institution - 1897 - 300 pages
...SURFACE. An expression for the area of a zone of the earth's surface or of a quadrilateral bounded by meridians and parallels may be found in the following...— The area of an elementary zone dZ, whose middle latitude is ф and whose width is i>m a<f>, is (see FIG. i), dZ = 2 IT f pm аф -~ - ~ (¡,., />..... | |
 | Smithsonian Institution - 1897 - 982 pages
...SURFACE. An expression for the area of a zone of the earth's surface or of a quadrilateral bounded by meridians and parallels may be found in the following...— The area of an elementary zone dZ, whose middle latitude is ф and whose width is pm ¿ф, is (see FIG. i), dZ = 2 я- г рт аф = 2 Я- pm pn COS... | |
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QUADRILATERALS OF THE EARTH'S SURFACE. An expression for the area of a zone of the earth's surface or of a quadrilateral bounded by meridians and parallels may be found in the following manner : — The area of an elementary zone dZ, whose middle latitude... 