ONE HUNDRED THOUSAND FACTS FOR THE PEOPLE. 413: 



MEASURE, Board.— The unit of Board 

 Measure is a square foot one inch thick. 

 Hence, to measure boards, if one inch 

 thick, multiply the length in feet by the 

 breadth in inches, and divide by 12. If 

 the board taper, multiply by half the width 

 of both ends added. Sawed lumber, like 

 foists, plank and scantling, are now bought 

 and sold by board measure. Hence, to 

 measure them, multiply the width in inch- 

 es by the thickness in inches ; multiply 

 the product by the length in feet, and di- 

 vide by 12. The number of feet, board 

 measure, which can be sawn from a given 

 log, can only be approximately determin- 

 ed from general tables. The following 

 table is the standard commonly adopted 

 for logs 10 feet in length, and of diame- 

 ters indicated, measured under the bark at 

 the smaller end. 



Ft. Diam. Ft. 



225 36 640 



250 37 681 



375 38 723 



302 39 765 



330 40 810 



360 41 850 



391 42 903 



422 43 952 



456 44 1000 



490 45 1051 



526 46 1 103 



562 47 1 1 56 



601 48 1210 



Diam. Ft. Diam, 



10 23 23 



11 31 24 



12 40 25 



13 50 26 



14 62 27 



15 75 28 



16 90 29 



17 105 30 



18 122 31 



19 140 32 



20 160 33 



21 180 34 



22 202 35 



To find the contents in board measure 

 of a log of any length, look for its diam- 

 eter in the table, take the corresponding 

 number of feet, point of one place, and 

 multiply by the length of the log. 



MEASURING, the Height of Trees.— 

 It is often desirable to determine the 

 height of a tree, if not with mathematical 

 correctness, with something approaching 

 to accuracy. There are instruments made 

 for the purpose of measuring with great 

 precision, but there are several methods 

 by which the height can be ascertained 

 without expensive appliances. By meas- 

 uring the shadow of a rod or other ob- 

 ject ot a known length and the shadow 

 of the tree, a simple sum will give the 

 height. Suppose that we measure the 

 shadow of aperpendicular rod six feet long, 

 or that of a man of the same height, and 

 find it to measure eight feet, and then 

 measure the shadow of the tree and find 

 it to be one hundred and thirty-two feet; 

 then 



as S ft. : 6 feet. : 133 feet. : 99 ft. 



The Gardeners' Chronicle figures a sim- 

 ple quadrant for tree-measuring, which 

 we here explain. A quarter of a circle is. 

 made of some light wood, and a small 

 plumb-bob is suspended from what would 

 be the centre of the circle, and a mark 

 made just half way of the curved side of" 

 the quadrant. Two small eyes for sights 

 attached to one of the straight edges 

 makes the implement complete. The 

 quadrant is held by the operator, moving 

 backward or forward until he can see the 

 top of the tree through both sights, the 

 plumb-line at the same time hanging over 

 the mark. The distance of the observer 

 from the tree, when he can see the top of 

 it in this manner will be the height of the 

 tree. Allowance must be made for the- 

 height of the eye from the ground, and 

 for any difference in the lever of the- 

 ground between the tree and the ob- 

 server. 



Another Mode. — In his tale of Mon- 

 sieur Violet, Captain Marryat tells us, as 

 an instance of the great aptitude for ap- 

 plying simple rules possessed by the Shos- 

 nonee Indians, that when they desired to 

 measure the height of a tree at any time- 

 when its shadow is cast on the ground, 

 they used to place a stick at a given 

 length into the ground, and then, calcu- 

 lating the difference between the length 

 of its shadow and its actual height, and 

 applying the same to the shadow of the- 

 tree, they ascertained its correct height,, 

 thus unknowingly working out a sum in 

 the rule of three. Any person, however- 

 ill-informed, might easily get at the exact 

 height of a tree when the sun shines, or 

 during bright moonlight, by marking two 

 lines on the ground three feet apart, and 

 then placing in the ground on the line 

 nearest to the sun a stick that shall stand 

 exactly three feet out of the soil. When 

 the end of the shadow of the stick exact- 

 ly touches the farther line, then also the 

 shadow of the tree will be exactly in 

 length the same measurement as its- 

 height. Of course in such a case the sun 

 will be at an exact angle of 45 ° . Meas- 

 urements of this character could be best 

 effected in the summer when the sun is, 

 powerful, has reached to a good height in 

 the heavens, and when ' the trees are- 

 clothed with living green, so as to cast 

 a dense shadow. To many to whom this 

 idea might not have occurred it might be. 



