23 



more readily than through non-conducting vacant air. In this country the 

 amount of danger by hail is so small that no artificial protection is deemed 

 necessary. 



TREES PURIFY THE AIR. 



Forests afford other incidental benefits to man besides their effect in 

 modifying the climate, 'aflbrding a supply of wood, &c. They purify the air 

 by absorbing the carbonic aeid gas, whicli, when existing in sufScient quan- 

 tity, is destructive to animal life, and by emitting, at least during sunshine, 

 oxygen gas. They are supposed also to destroy that unknown something that 

 we call miasm in the air, and thus prevent siekness. 



TREES ENRICH THE LAND. 

 By their annual quantity of leaves, detached bark and twigs, and by their 

 fallen trunks, they supply the soil with a larger amount of vegetable matter 

 than they consume, so that its fertility is always increasing; they constitute 

 •one of the grand provisions of nature for the restoration of exhausted lands. 

 Newly cleared land is always most productive ; and leaf mould is nought for 

 ■by the skillful gardner, as the soil most to be relied upon, when he wishes to 

 rear some rare and delicate flower ; it is the richest in the elements of plant- 

 growth of any kind of natural soil. 



SUMMARY VIEW OF FACTS AND CONSEQUENCES. 



While there is no doubt but that these very decided changes of climate 

 can be produced by man, by the rearing or by the destruction of forests, it 

 must be remembered that after all, they do not materially change the great 

 climatic laws due to the latitude in which we live ; thoi^h we can protect 

 the ground occupied by our growing crops from the fierce winds; those winds 

 will not cease to blow ; though we can secure shade, the piercing rays of the 

 sun will in no wise be abated , and though we may prevent the undue evapo- 

 ration of water from the soil, the quantity of rain will be but little if any 

 changed. We here have the ready explanation of the .great differences of 

 of opinion upon this subject among men ; the changes b«ing local and not 

 generaL It may be true that the annual quantity of heat received from the 

 eun upon a given quantity of land is the same through all t me, yeit it will be 

 found to make a vast difference with the condition of that land, whether this 

 iheat is, or is not, permitted to strike the ground. 



From the facts already given above it must be quite evident that clearing 

 away the forests of Wisconsin w U have a very decided effect upon the cli- 

 mate and productions, and therefore upon the inhabitants themselves. The 

 summers will become hotter and more oppressive; the winters colder ; both 

 the cold blasts of winter and the hot winds of summer will have full unob- 

 structed sweep over the land ; the dryness of the groiind will be increased ; 

 springs dried up ; rivers cease to flow at some seasons of the year, and be- 

 vcome £reat floods at others ; .the soil on sloping hills washed away ; loose 



