zoo THE POPULAR SCIENCE MONTHLY. 



to ascertain. Different localities would no doubt require a different 

 proportion. Rentzsch (quoted by Marsh) estimates that for the interior 

 of Germany about 23 per cent., and along the coast 20 per cent., is 

 necessary for the needed protection. The case hardly admits of such 

 precision ; more would no doubt be better, and in a dry climate like 

 ours, more than anywhere else. 



So rapidly is the destruction of timber going on in this country 

 that many localities originally covered with forest have not so great 

 a proportion as this remaining, and other localities are in a fair way 

 soon to be in the same condition. This is becoming, or at least should 

 become, a real cause of apprehension to those who have the welfare 

 of the farming interest, and especially of the fruit-growing interest, at 

 heart. This continuous destruction of timber must eventually result 

 in injury to the market value of lands in certain neighborhoods, espe- 

 cially lands for fruit-growing purposes. 



The remnants of forests in the States have another enemy as inex- 

 orable and remorseless as the woodman's axe. Many forest-trees, like 

 the wild Indian, do not seem to flourish in the midst of civilization. 

 They first show signs of decay at the top. This takes place after the 

 underbrush has been cleared away and the surface has lost that perfect 

 mulch of decayed leaves which belongs to native forests. The trees 

 are now liable to suffer from extremes of drought as never before. 

 This change is equal to a change of habitat, and the consequence to 

 some varieties of trees is loss of health and vitality. 



According to the experiments of Prof. Pfaff made on an oak-tree, 

 the amount of moisture lost by transpiration during the summer- 

 season was more than eight times the quantity of rainfall on the same 

 area for the same time. Dr. Hahn, who thinks this estimate quite too 

 high, says, nevertheless, that " Herr Pfaff 's results show us what an 

 enormous quantity of water is required by isolated trees in a com- 

 paratively dry and free (bewegten) atmosphere, and how much they 

 need the protection which they afford to each other in their combined 

 capacity as a forest." Whenever the balance and integrity of the 

 original forest is broken, the supply of water during droughts not 

 being equal to the demand of trees now suffering the double disadvan- 

 tage of needing more moisture and less of it available than before, 

 death begins in the topmost branches, that part of the tree which is 

 most exposed to the conditions of active transpiration and farthest 

 removed from the source of moisture. 



What should we do about this blight ? Save the timber by using 

 it before it is injured, and plant enough to make up for the loss. 



For the application of the facts as now ascertained, let us take the 

 southern shore of Lake Erie, which is a good fruit-region lying mid- 

 way between the Eastern and Western cities, and affording to both part 

 of their supply of fruit. Fruit does not do so well here now as it did 

 in the early settlement of the country. Cut off the timber which still 



