86 BOARD OP AGRICULTURE. 



that is, plants are known to absorb, during the night, a small 

 amount of oxj'g'en, and throw out a small amount of carbonic acid. 

 But during the twenty-four hours, the amount of oxygen thrown 

 to the air is very much greater than the amount absorbed, and the 

 amount of carbon appropriated very much greater than the amount 

 given out, so that on the whole, they act as purifiers. 



Gov. Brown. I think every gentleman present will realize the 

 force of the remark in the excellent lecture to which we have 

 listened in regard to the effect of trees in ameliorating the tern- 

 perature of the atmosphere, if he M^ill call to mind how he stood 

 in the street yesterday or this morning, conversing with a friend, 

 when the wind blew by him pretty rapidly, and caused him to be 

 so cold that he retreated round the corner to the shelter of the 

 buildings. Your body is in the same condition as the ground on 

 the western side of this hedge. It contains a certain amount of 

 heat, and when a current of air sweeps over it, it carries away a 

 portion of the warmth of the body. So in the case of the hedge. 

 The cold wind sweeps through it, with its thousands and tens of 

 thousands of branches and twigs, and all the time the solar rays 

 have been darting down on the west side of the hedge and warmed 

 the earth, and the earth is radiating heat into the atmosphere con- 

 tinually. I realize this «very year of my life. I have a hedge on 

 the northwest side of my garden, and I can work all day on the 

 southwest side of the garden, when I could not stand it an hour 

 on the northeast side. The ground remains frozen there for weeks 

 after I can go to work on the southwest side. 



I only mention this to show that we can gain a great deal by 

 planting trees on our farms. The most remarkable case that I 

 know of is at Nahant, in Boston harbor. Mr. Tudor — the man 

 who introduced the ice trade between this country and foreign 

 countries — lived on the island. Having a great taste for garden- 

 ing, and everything of the kind, he planted trees there, but could 

 not make them grow. At length it occurred to him to make a 

 fence on the easterly side of his garden. He did so, and then he 

 found he could make trees grow pretty well ; but he found that by 

 putting up a high fence with small spaces between the slats, the 

 trees grew a great deal better than with a light fence, because the 

 cold air was warmed and its force broken as it passed through 

 that fence. Mr. Tudor died a few 3'ears ago, but before he 

 died he succeeded in covering those rocks (for there was very 



