24. Diagram showing comparative progress of yields of spruce, fir, pine, and beech 25. Iron dibble used in setting out small pine seedlings... 244 247 29. Buds of maple. 26. Tree classes: Classification according to crown development 27. Physiological importance of different parts of the tree; pathways of water and food materials. 28. Bud development of beech 30. Dormant bud on a 12-year-old branch of beech 253 269 270 270 271 31. Section through a 12-year-old stem of beech, showing manner of bud and limb formation. 32. Section through a partly decayed knot in oak wood. 44. Differences of soil temperature (woods and open fields). Comparison of deciduous and evergreen trees (W-O)... 45. Difference of soil temperature (W—O), all stations-German observatories.......... 319 320 46. Differences of soil temperature (woods and open fields). Comparison of elevations above sea level (W-O) 320 47. Differences of temperature for young trees, Lintzel Station, woods and open fields (W—0) 48. Effects of litter on soil temperature (littered surface-bare). (W-0) 49. Difference of soil temperature, under sod and bare surface (sod—bare). Becquerel's observations... 50, 51, and 52. Forest air temperature, difference of woods and open fields (W-O), deciduous trees, evergreen trees, and young forest (Lintzel)....... 53. Forest air temperature differences, W-O. German stations 320 321 321 321 322 54, 55, 56, 57, and 58. Forest air temperature differences, woods and open fields (W—O), at Friedrichsrode, Hagenau, Sonnenberg, Eberswalde, Schoo, Marienthal, Hadersleben, and average 59, 60, 61, 62, and 63. Forest air temperature differences, woods and open fields (W-O) at Marienthal, Hadersleden, elevated stations, near sea level-average. 323 324 64. Forest air temperature differences for the year at height of the tree top (W—O). 65. Average differences of tree-top temperature, sixteen German stations (W-O).......... 325 325 66, 67, 68, 69, and 70. Tree-top temperature, differences (W-O) at Friedrichsrode, Eberswalde, St. Johann, Carlsberg, and Schoo..... 326 71, 72, 73, 74, and 75. Tree-top temperature differences, German stations (W-O), Sonnenberg, Kurwien, Hagenan, and Neumath-deciduous trees..... 327 76. Tree-top temperature differences, German stations, evergreen trees.. 328 77. Vertical temperature, gradient in woods, degrees Fahrenheit, for a hundred feet.. 78. Vertical temperature gradients from observations above trees... 328 328 79. Forest temperature differences above trees, from Fautrat's observations 80. Evaporation and precipitation 328 329 81. Monthly evaporation in the fields (upper curve) and woods (lower curve), in inches 82. Percentage of evaporation in the woods as compared with that in open fields......... 83. Ratio of evaporation from water surface in fields and forest to precipitation. 84. Percentage of evaporation in woods to that in the open air. 85. Method of chemical analysis of turpentine.. 86. Method of distillation of turpentine.. 87. Distribution of turpentine in trees 329 329 329 329 336 337 339 FIG. 88. Relationship of different parts of same disk.... 89. Yield of volatile oil from constant quantity of turpentine............... 90. Diagram of detail analyses, representing radial dimensions of test pieces in each disk 91. Variation of weight with height of tree .... 92. Schematic section through stem of longleaf pine, showing variation of weight with height, diameter, and age. 93. Variation of compression strength with moisture. 94. Loss of water in kiln drying and reabsorption in air, shrinking and swelling 95. Relation of strength in compression end wise to weight of material..... 96. Relation of weight to bending strength at rupture.... 97. Strength of contiguous blocks, showing maximum uniformity of select quarter-sawed material in compression end wise....... 98. Relation of fiber stresses and distortion 99. Distribution of internal stresses in a beam at rupture...... 100. Position of neutral axis and internal stresses at rupture of beam. 101. Fiber distortion in unit length of beam at elastic limit 102. Position of neutral plane at rupture. 103. Method of sawing test logs..... 104. Apparatus for determining specific gravity 105. Result of physical examination (sample).. Page. 340 340 344 350 351 353 354 367 368 370 373 373 373 374 375 385 386 389 A. MEMORIAL TO CONGRESS. MEMORIAL OF A COMMITTEE OF THE AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE ON BEHALF OF FOREST PRESERVATION, LEADING TO THE ESTABLISHMENT OF THE DIVISION OF FORESTRY. [From Senate Ex. Doc. 28, first Session Forty-third Congress, or Report No. 259, H. R., first Session Forty-third Congress.] At the meeting of the Association for the Advancement of Science held at Portland, Me., on the 22d day of August, 1873, the following resolution was passed: Resolved, That a committee be appointed by this association to memorialize Congress and the several State legislatures on the importance of promoting the cultivation of timber and the preservation of forests, and to recommend such legislation as may be deemed proper for securing these objects. Also, that this committee be instructed to cooperate with national associations for a similar object. The committee appointed consisted of Franklin B. Hough, Lowville, N. Y.; George B. Emerson, Boston, Mass.; Prof. Asa Gray, Cambridge, Mass.; Prof. J. D. Whitney, San Francisco, Cal.; Prof. J. S. Newberry, New York City; Hon. Lewis H. Morgan, Rochester, N. Y.; Col. Charles Whittlesey, Cleveland, Ohio; Prof. William H. Brewer, New Haven, Conn., and Prof. E. W. Hilgard, Ann Arbor, Mich. Under this appointment consultation has been had among members of this committee, who have requested the undersigned, on their behalf, to represent as follows: That the preservation and growth of timber is a subject of great practical importance to the people of the United States, and is becoming every year of more and more consequence, from the increasing demand for its use; and that while this rapid exhaustion is taking place, there is no effectual provision against waste or the renewal of supply. We apprehend that the time is not distant when great public injury must result from this cause, and we deem it to be our duty to urge upon the Government the importance of taking timely action in providing against the evils that must otherwise follow. Besides the economical value of timber for construction, fuel, and the arts, which is obvious without suggestion, and must increase with the growth of the nation, there are questions of climate that appear to have a close relation to the presence or absence of woodland shade. The drying up of rivulets, which feed our mill streams and navigable rivers and supply our canals, the failure of the sources which supply our cities with pure water, and the growing tendency to floods and drought resulting from the unequal distribution of the rainfalls since the cutting off of our forests are subjects of common observation. In European countries, especially in Italy, Germany, Austria, and France, where the injuries resulting from the cutting off of timber have long since been realized, the attention of governments has been turned to this subject by the necessities of the case, and conservative measures have in many instances been successfully applied, so that a supply of timber has been obtained by cultivation, and other benefits resulting from this measure have been realized. Special schools of forestry have been established under the auspices of government, and the practical applications of science in the selection of soil and conditions favorable for particular species, and in the planting, care, and removal of timber, are taught and applied, with the view of realizing the greatest benefits at the least expense. 37 There is great danger that, if not provided against, the fearful changes may happen to our largest rivers which have taken place on the Po and other large rivers of Italy, France, and Spain, caused by the destruction of the forests from which came their tributaries. These forests had retained the water from the snows and rains of winter and spring, and supplied it gradually during the summer. Since their destruction the rain falling in the rainy season comes down almost at once, bringing with it earth and stones, deluging the banks of the larger streams, but leaving a very insufficient provision for evaporation and against the consequent drought of summer. Thus, when the forests about the sources of our great rivers shall be cut away, the water from the melting snows and early rains will be liable to come down in vast floods, overflowing the banks and carrying ruin and destruction in their course, while the affluent streams in summer will diminish or disappear, to the great injury of the country through which they flow. We deem it highly important that the true condition and wants of the country in this regard, and the injuries that may result from the destruction of the forests and the exhaustion of our supplies of timber, should be known in time to provide a remedy before the evils are severely felt. There are facts of the greatest importance in relation to the past and present destruction of forests, the pressing want of timber trees in States without natural forests, and the changes that have taken place, or are taking place, in consequence of the destruction of the forests, that should be carefully collected and be widely and familiarly known. A knowledge of these facts would be everywhere of great value. They should be gathered, arranged, and so widely published as to reach the intelligent inhabitants of all the States. There is not a State or Territory without a direct interest in the subject. We should know the experience of other countries and be able to apply whatever may be found therein suited to our soil and climate and consistent with the plan of our government and the theory of our laws. Individual or associated effort, unless organized and directed by authority, could not be expected to conduct these inquiries or make known the results with that fullness which the investigation would require. We therefore recommend them as worthy of the attention of Congress, as the immediate guardian of the Territories and the proper source of power in whatever concerns the interest of the whole country. We would therefore respectfully request the passage of a law creating a commission of forestry, to be appointed by the President and Senate, and that it should be required to ascertain, from the most effectual and reliable means within its power, and to report to Congress upon the following subjects: First. Upon the amount and distribution of woodlands in the United States, the rate of consumption and waste, and the measures that should be adopted to provide against the future wants of the country in the preservation and planting of timber. With this there should be an inquiry concerning the importation and exportation of lumber and other forest property. Second. The influence of forests upon the climate, and especially as to what extent their presence or absence tends to affect the temperature, rainfall, and other atmospheric conditions upon which agricultural success depends. Third. A full statement of the methods practiced in Europe in relation to the planting and management of forests, and an account of the special schools of forestry that have been established in foreign countries. Respectfully submitted. FRANKLIN B. HOUGH, On Behalf of the Committee of the American Association for the Advancement of Science. WASHINGTON, D. C., February 6, 1874. |