. Plants and their uses; an introduction to botany. Botany; Botany, Economic. 250 INDUSTRIAL PLANTS its separation into more (jr less delicate strantls when erushed. Those who have had experience in chopping wood know that the ax cleaves as a rule most easily when cutting to-ward the center of the log; less easily in any other lengthwise direc- tion, and least easily when directed slantingly or directly across the grain. This shows that the structural parts have a peculiarly definite arrangement. Something of this appears when we examine, for example, with a strong magnifier, the surface of a
. Plants and their uses; an introduction to botany. Botany; Botany, Economic. 250 INDUSTRIAL PLANTS its separation into more (jr less delicate strantls when erushed. Those who have had experience in chopping wood know that the ax cleaves as a rule most easily when cutting to-ward the center of the log; less easily in any other lengthwise direc- tion, and least easily when directed slantingly or directly across the grain. This shows that the structural parts have a peculiarly definite arrangement. Something of this appears when we examine, for example, with a strong magnifier, the surface of a piece of pine wood, cut radially, ('. e., toward the center of the log. We see, as shown in Fig. 229, that the wood is made up mainly of very slender, thin-walled tubes »liiilll!!IM li I'lif". Fu;. 2129.—R;L(.li:il .sc-etioii of wiiitc pim- wood. Ma^^iiifiod about 50 diame- ters. ie>ri>j;iiial-) each and tapering at the emls; and besides these are numerous flat bundles of much smaller tubes running at right angles to the others and rai-liall>-. These bundles of finer structure are called pitJi-niijK because they ar(^ .some- what similar in texture to a cylinder of piUi in the center of the log, anil .some of them al least, are extensions of it. Their relative softn(>ss makes the wood most easily separated along the ])lanes in which they lie. Even to the n:ik<'d e\'e tlieir ])i'ciiliar si n makes the ])ith-rays :ii)i)arent on a radial silffaee, and gi\'es an es|)eeiall\' at(racti\'e |)ri)minence to them in what the dealers (•.•ill " (|uarter-sawed " timber. It is plain als(j that thv Jtliril--<, by which name we shall understand. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Sargent, Frederick Leroy, 1863-. New York, H. Holt and Company
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
