348 MASSACHUSETTS AGRICULTURE. 



quantity of manure which was used upon the twenty acres in 

 the previous system of culture, to be made to yield an equal 

 amount of produce. If five hundred dollars worth of manure 

 would obtain five hundred dollars of net profit from twenty 

 acres, would it require the same quantity, or less, or more, to 

 obtain the same profit from ten acres ? Would the increased 

 productiveness of the soil, trenched and worked, and manured 

 in such a manner as to be raised to its greatest capacity, pay 

 our farmers for pursuing such a system, or approximating to it, 

 throughout their own husbandry ? 



10. What influence has the cultivation and draining of the 

 soil upon the temperature of the local climate ? * Is the atmos- 

 phere resting over a certain tract which is naturally wet, ren- 

 dered warmer by perfect drainage ? What is the difference of 

 temperature at the time such a difference exists, in two contig- 

 uous fields on the same level, and originally of the same char- 

 acter, one of which remains in a wet and boggy condition, 

 while the other is thoroughly drained, and converted into a dry 

 and friable soil ? At what season and at what period of the 

 twenty- four hours, is this difference of temperature perceptible ? 

 There is reason to believe that it is very considerable during 

 the summer, especially on summer nights. Wet lands radiate 

 more heat than dry lands, and this heat escapes into the higher 

 atmosphere. Hence the great liability of low lands to be affected 

 by spring and summer frosts. The influence of drainage upon 

 the local temperature of any tract, is a curious subject of inves- 

 tigation. The advantage of draining, in order to insure good 

 crops, is well known and admitted on all sides. How much 

 does the consequent change of local temperature contribute 

 towards producing these superior crops ? Many a farmer whose 

 lands are wet, and whose situation is comparatively cold in 

 summer, would render his home more comfortable and his farm 

 more productive, by perfect drainage. 



A series of experiments should be instituted, to ascertain, as 

 nearly as practicable, the precise am^mt of benefit accruing to 

 the local climate, from thorough and extensive drainage. The 

 subjects of inquiry are not only the amount of change effected 

 in the temperature, but also the time of the day and of the year 



* This question is more fully discussed by the author, in Ilovey's Magazine 

 for November, 1857. 



