INDEX. 



Abbe, Prof. Clevpland, detcrtnination of the true 

 amount of ])reci])itati(>u aiitl its bearing ou 

 theories of foi'est influences, 175. 

 Air currents, effects of forests on, 18, 120. 

 Air humidity: 

 per cent of, 16. 



in woods, glades, and plains, compared, 102. 

 relative, 103. 



Fautrat's observations, 104. 

 Libiirnau's ronchisions, 104. 

 Air temptra lures : 



in interior of forests, 14, 51. 



difference between forests and-open ticlds, 51. 



aunual range, 52. 



monthly range, 53. 



deciduous and evergreen fctrests, 58. 



effect of elevation, 60. 



effect of young forests, 00. 



temperatures in tree crown and above trees, 



15, 61, 

 temperature gradients, 68. 

 Fautrat's observations above trees, 70. 

 vegetation, effects on air temperatures, 76. 

 effect of evaporation, 81. 

 temperatures in glades, forests, and tields, 83. 

 Swedish observations, 85. 

 conclusions, 88. 

 Alps, French, effect of denudation, torrents, area 



needing to be reforested, cost, 150. 

 Austria, systematic observations in forest mete- 

 orology, 33. 

 Becquerel, M., meteorological observations, 27, 



49, 73, 103, 111, 119, 121. 

 Bohemia, observations regarding influences of 



forests ujiou precipitation, 126. 

 Brazil, observations regarding influences of for- 

 ests upon preLii)itation, 128. 

 Carbon, annual production by plants, heat ab- 

 sorbed by assimilation of carbon, 82. 

 Chinook, effect on temperature, 133. 

 Climate: 



effect of forests on, 9, 17, 23, 24. 

 general and local, 10. 



literature of forest influence on, m(*tJiods of 

 determining such intlueuce, imperfect in- 

 struments and observations, 25. 

 no certainty that a given change of climate is 



due to Giiange in forest conditions, 26. 

 secular changes, 26. 

 Dr. Liburnau's conclusions, 34. 

 (See also Meteorology and Water supply.) 

 Climati<; illustrations, 189. 

 Climatology, forest, two problems, 23. 

 methods of investigation, 23. 



12144— No. 7- 



-13 



Curtiss, George E., analy-sis of the causes of rain- 

 fall, with special relation to surface condi- 

 tions, 187. 

 Currents, air. (See Air currents.) 

 Congress : 



of German foresters and farmers at Vienna, 



1868, 35. 

 international meteorological, at Vienna, 1880, 

 36. 

 Denudation, effect in French Alps, 159. 

 Drainage: 



influence of forests upon, 20, 141, 157. 

 retardation of watertlow by forests, 158. 

 experience in the French Alps, 159. 

 examples of the influence of forests on water- 

 flow, 162. 



{See also "Water supply.) 

 Ebermayer, Dr., meteorological observations, 30, 



75, 99, 146, 148, 150, 171. 

 Evaporation : 



per cent in field and forest, 16. 

 influence of forests upon, 20, 96, 132. 

 annual, in Holds and woods compared with 



precipitation, 96, 100, 134. 

 influenced by wind, 133. 

 reduced bj' forests, 138. 

 modified by trees of different kinds and .ages, 



98. 

 amount from bare soil and water surface, 99. 

 effect of litter on, 99. 

 Fautrat, M., observations, meteorological, 29, 69, 



103, 108, 125. 

 Fernow, B. E.: 



article — introduction and summary of con- 

 clusions, 9. 

 relation of forests to water supplies, 123. 

 notes on the sanitary significance of forests, 171. 

 Filtration: 



process, 139. 



Wollny's experiments, 148. 

 relation to floods, 150. 

 influence of various soils upon, 150. 

 influence of grass cover, 150. 

 influence of snow, 152. 

 influence of the forest floor, 152. 

 Forest influences. {See also Meteorology, forest.) 

 influence upon climate and waterflow, 9. 

 reasoning from insufHcieiit premises, need of 



further exact observations, 10. 

 water management depend<mt upon forest 



maiiagemcut, 12. 

 summary of conclusions, 13. 

 ditl'eience of meteorological conditions within 

 and without the forests, 14. 



193 



