132 GRASSES AND FORAGE PLANTS. 



to one luindred inches, and that the atmosphere when at the 

 freezing point contains about a two-hundredth part of its weight 

 of water, while at 52° it contains a hundredth part, or twice as 

 much; at 74°, a fiftieth part, or four times as much, and at 98°, 

 a twenty-fifth part, or eight times as mucli, and so on in that 

 ratio. Now although the mean annual temperature of the two 

 countries is about the same, — it being near London about 48° 

 5', and at Boston 48° 9', — yet the temperature of the growing 

 months of the two countries presents a marked dilTercnce, the 

 mean temperature of ev^ery one being with us much higher. 

 But the climate of England is proverbially moist, notwithstand- 

 ing that the mean annual fall of rain near London is only little 

 over twenty-five inches, while the quantity which falls at Boston 

 is over forty-two inches. The amount of sensible moisture of 

 the atmosphere is greater in England than here, though the 

 actual amount existing in our atmosphere must excee i that of 

 the atmosphere even in the eastern part of England. Our 

 soil is consequently dryer, and unless we have frequent rains 

 vegetation suffers sooner, and the growth of grass is liable to be 

 checked for the want of moisture. This actually happens more 

 or less nearly every year. But the spring of the past year was 

 an exception, for the quantity of rain in most parts of the State 

 was no only somewhat larger than usual, but it was well dis- 

 tributed over the spring months ; that is, it fell frequently and 

 in small quantities. This, as is usually the case, caused an 

 early and remarkably luxuriant growth of grass, while the 

 quality was not generally considered so good as the average. 

 It may be laid down as a well-fixed principle, that the grass 

 crop is better from large quantities of rain falling at once and 

 at longer intervxls. — provided it does not come in torrents to 

 prostrate the crop, and that the intervals are not so long as to 

 produce droughts, which arc always attended with deleterious 

 effects, — than "from smaller quantities falling with greater fre- 

 quency. The quantity in the latter case will not ordinarily be 

 so great as in the former, but it is more than com})ensated, it 

 is thought, by tlie increased value. More accurate statistics 

 will throw light on this subject. 



As a means of comparison, the following table of the mean 

 monthly temperature and rain at the observatory at Cambridge, 

 during the growing luonths of 1854, '55 and '5G, will l)e found 



