THE TREES OF AMERICA. 53 



cities of antiquity, mementos of the mighty races which, have passed away, might 

 have been preserved to us from the all-conquering sand by " ranks of trees." 



Trees prevent the drifting of snow. This is important to all cultivators of 

 the soU, as, if the snow lies level, the ground is prevented from exposure to 

 sudden changes of temperature, which are the principal sources of mischief to 

 vegetation during winter and spring. There is also, as we have seen, much less 

 liability to freshets, as the ground is in a better condition to receive and retain 

 the water produced by melting snows and ice. This fact is also important in 

 regard to keeping in order common roads in winter, and also of special im- 

 portance to railroads, as a very large item of expense is occasioned in clearing 

 the track in winter of snow and ice, to say nothing of the expense of additional 

 fuel, the wear and tear of engines and cars, etc. In order to obtain some facts 

 upon this important point, the author, during the past year, 1857, sent a cir- 

 cular to the ofhcers of some one hundred of our railroads, and received in 

 substance the following reply : — 



Answer to question 1. We have never been troubled with snow drifts where 

 the road is protected by trees. 



2. Two rows of evergreens, planted in the manner you describe, (that is, the 

 trees three feet apart, the rows the same distance, so that those in one row would 

 be opposite the blank spaces in the other,) would ordinarily afford sufficient pro- 

 tection. 



3. Three or four rows of pines, of a few feet in height, if thrifty, or an equiv- 

 alent amount of underbrush, would protect the roads. 



4. Level snows, however deep, offer but little obstruction. 



5. If the road passes through the forest, and the wind, during a storm, is in 

 a line with the road, still the snow lies level, and offers but little if any ob- 

 struction. 



6. More fuel is consumed in the open country than in the woods. 



7. An engine will burn more fuel when there is a high wind, though it be a 

 " fair wind ; " but when blowing in an opposite direction to the passing train, 

 the consumption of fuel will be increased twenty or twenty-five per cent., if the 

 train is run at its usual speed. 



