The woodsman's handbook (1912) (14597457267)

Identifier: woodsmanshandboo36grav_1 (find matches)

Title: The woodsman's handbook

Year: 1912 (1910s)

Authors: Graves, Henry Solon, 1871-1951 Ziegler, E. A. (Edwin Allen), 1880-

Subjects: Forests and forestry Measurement Handbooks, manuals, etc Lumbering Handbooks, manuals, etc

Publisher: Washington, D.C. : U.S. Dept. of Agriculture, Bureau of Forestry

Contributing Library: U.S. Department of Agriculture, National Agricultural Library

Digitizing Sponsor: U.S. Department of Agriculture, National Agricultural Library

Text Appearing Before Image:

y the distance between the upper and lower visionpoints on the second pole by the longer of the other two measure-ments and divide by the shorter; the result will be the height ofthe tree. Example: Let ab=6; Sh=4; and SB=30, then^^=45,heightof tree. Another method sometimes used is as follows: The observerwalks to a distance from the foot of the tree about equal to itsestimated height. He then lies on his back, stretched at fulllength (fig. 7), and an assistant notes on a vertical staff erected^. M. INSTRUMENTS USEFUL TO A WOODSMAN. 99 at his feet, the exact point where his line of vision to the top ofthe tree crosses the staff. The height of this point from the groundBC is measured and his own height from his feet to his eyes AB. Then: AB: BC=AJ): DE. beJ^^^^ AB Example: Let J(5=6; BC=b\ ^D=60; thenof tree. Faustmanns Height Measure. 5X606 =50, height This instrument, shown in figure 8, consists of a skeleton rectan-^ ^ gular metal frame ha\dng two crossbars at one side of its longi-

Text Appearing After Image:

FiG. 8.—Faustmanns height measure. tudinal center, the frame and bars being in one piece. A slide,reversible end for end and having beveled edges, works in under-cut grooves formed in the inner edges of the crossbars. This slideis provided at its ends with thumb notches, and with transverselyarranged index marks, designated I and II. A plumb line carryinga plummet is attached to the slide in the center of the indexmark II. A retaining spring secured to the back of the frame andbearing against the inner face of the slide holds it in any position 100 THE woodsmans HANDBOOK. ^ in which it may be set. The left-hand end bar of the frame isfurnished with an eyepiece, and the right-hand end bar with anobjective, these being made of metal and hinged so as to be foldeddown out of the way when the device is not in use. A long, nar-row mirror, hinged to the frame at a point below the objective, isfurnished to reflect a right-hand horizontal scale and a left-handhorizontal scale engraved upon t

the woodsmans handbook 1912 книжные иллюстрации сельское хозяйство лесное хозяйство лесозаготовка Министерство сельского хозяйства США изображения из интернет-архива

1912

U.S. Department of Agriculture, National Agricultural Library

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public domain