20 



hedge, only a few feet in thickness, formed a very imperfect screen when 

 compared to a mass of trees several rods in breadth." 



Wall protection is well known to gardeners, and every skillful horticultur- 

 ist is aware that tender plants will survive the severe winters when surround- 

 ed or overshadowed by evergreens, that would die without such surroundings; 

 and every woodsman knows equally that the ground seldom freezes in the 

 thick set forests. Every observant farmer must have seen his young plants 

 of grass and grain frozen up by the frosts, beaten about and torn entirely 

 from the ground by the winds. 



If tree belts in New Jersey have been known to increase the production of 

 the land fifty per cent. ; and if one half of this increase could be realized in 

 Wisconsin, the surplus farm products of the year 1866 wquld have netted the 

 state the sum of $l'7,3OO,O0O. This sum would have been added to the 

 wealth of the state with but very little additional expense. The estimated 

 value of nine of the principal crops of 1866 is $69,500,000. 



If lands could be made to yield one-fourth more income, their value is in- 

 creased correspondingly ; and the hundred and twenty milions aggregate 

 value of farm lands in the state becomes $167,600,000. 



If the extreme cold of winter can thus be moderated, it would prevent the 

 destruction or injury of many of the crops, and the finer fruits we attempt to 

 cultivate ; and thus extend northward the area over which they can be pro- 

 duced with certainty. 



But winter is not the only season of injury to crops. Sweeping tempests 

 beat down grain fields, level the heavy grass of the meadows, and break 

 down the corn. Orchards are severely whipped about, destroyed and dried 

 up by the blasts that sweep over them in summer. 



On the 14th and 16th of June, 1861, one of these very hot dry winds blew 

 from the south-west over a considerable portion of southern Wisconsin and 

 northern Illinois ; its origin and progress has not been studied ; we know not 

 from whence it came, whither it went, nor what further mischief it produced 

 in other portions of the country. Its effects upon young trees exposed to its 

 full influence, were like that of a hard frost, killing the leaves, which remain- 

 on the trees in a crisped, withered and blackened condition, for a number of 

 days afterwards. The effect upon the person was that of suffocation, and ex- 

 cessive dryness of the skin and throat. During its continuance the barome- 

 ter at Milwaukee fell from 29:69 inches on the morning of the ISth to 29:00 

 at 2 p. m. of the 16th; the " elastic force of vapor " in the air was dimin- 

 ished from an equivalent of 0.514 inches of mercury at 9 p. m. of the 14th to 

 0.350 at 2 p. m. of the 16th ; and the " relative humidity," or proportion of 

 moisture in the air, as compared with that which it was then capable of hold- 

 ing, was reduced from 69 per cent, at 1 p. m. of the 14th to 84 per cent, at 

 2 p. m. of the 15th. Sach extreme dryness is quite unusual even in Wis- 

 consin. 



Fruit trees, especially the more tender and valuable kinds were injured, the 



