. Forest mensuration. ther in the case of other clinometers this hypsometer may be used to readper cents of grade. The Winkler Hypsometer. The same principle may be used inconstructing a hypsometer in the form of a square or rectangularboard or cardboard. In this instrument the line of sight, AB, coin-cides with the top edge of the board. A board whose top and bottom edges are parallel is laid off with a 242 THE MEASUREMENT OF STANDING TREES horizontal scale at base and a vertical scale ad intersecting the scaleat base at right angles, at a point to permit this horizontal scale to
. Forest mensuration. ther in the case of other clinometers this hypsometer may be used to readper cents of grade. The Winkler Hypsometer. The same principle may be used inconstructing a hypsometer in the form of a square or rectangularboard or cardboard. In this instrument the line of sight, AB, coin-cides with the top edge of the board. A board whose top and bottom edges are parallel is laid off with a 242 THE MEASUREMENT OF STANDING TREES horizontal scale at base and a vertical scale ad intersecting the scaleat base at right angles, at a point to permit this horizontal scale to extendin both directions as in the Faustmann Hypsometer. Both scales aremarked off in the number of equal units or graduations desired, to cor-respond with the distance from the tree at which the hypsometer is tobe used. A plumb-bob is suspended from point a, and the heights aboveand below the eye read as usual. If but one fixed distance is desiredthis is represented by a scale reproduced on the line at base of Fig. 49.—The Weise hypsometer. This board may be graduated to read at lesser distances from thetree, by placing other horizontal scales upon the board intersectingthe vertical or distance scale ad at the point below the apex a,representing the distances desired, and graduating these horizontallines to the same scale as the base. This home-made hypsometer isdescribed in Farmers Bulletin 715, U. S. Dept. of Agriculture, 1916,p. 18. The original instrument from which this type of hypsometer wasderived is known as the Winkler hypsometer, shown in Fig. 50. Thisinstrument is also used as a dendrometer (§ 200). THE PRINCIPLE OF THE CHRISTEN HYPSOMETER 243 198. The Principle of the Christen Hypsometer. Many hypsom-eters have been invented, principally by Continental foresters, usingone or the other of these general principles. The Christen hypsometerintroduces a different principle but has no special merit except thesimplicity of its operation. Description of this ins
Size: 1752px × 1426px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectforestsandforestry
