818 



pressure, which may exphiin in pai-t the ilevchjpmciit of roots in the 

 soil, the physical action of manure, and the moxcmcnt of moisture in 

 the soil." 



A series of tables give results and daily observations for eight 

 months of mean, maxiininii. and minimum temperature of the air, 

 with the daily range; mean height of barometer; pressure of water 

 vapor in the atmosphere: mean dew-point : mean relative humidity; 

 rain-fall ; maximiun temperature by the solar radiation thermometer; 

 minimmn tempei-atur<' by the terivstrial radiation thermometer; dif- 

 ferences in temperature betwe(>n the terrestrial radiation thermometer 

 and the dew-i)()int: daily wind uKnement; mean, maxinnun, and 

 minimum tempei-ature of t!ie soil with daily range at depth of ?> to 9 

 inches, and mean weekly tem|)eraturt' of the soil at depths of 8, C), 9, 

 12, 18, and 24 inches. 



" The meteorological conditions of the Southern States are particu- 

 larly well adapted to the growth of cotton and rice, neither of which 

 can be grown economically at the North, while the yield per acre of 

 corn, wheat, and oats is only a third of the amount obtained at the 

 North and West. AVhile these facts may be due in part to the meth- 

 ods of agricultural practice, they are undoubtedly due in large part 

 to the general meteorological conditions of the respective localities. 

 * * * The larger rain-fall and liigher temperature at the South 

 gives us considerable more nu)isture in the air. the dew-point being 

 10 or 12 degrees higher than at the North. This gives almost twice 

 as much moisture in a given volume of air. * * * These differ- 

 ences increase as we go further south, and we tind in the really trop- 

 ical countries a very rank growth of vegetation, with naturally but 

 small fruit production. In the greenhouse plants can be made to 

 j)roduce only foliage, or to flower, or fruit, almost at will, by regulat- 

 ing the moisture supply. The higher temperattire and greater rain- 

 fall of the Southern States, therefore, will probably favor the produc- 

 tion of foliage oi' weed rather than grain production. This will ])rob- 

 al)Iy account, in hiru'e pai't. for tlie low average yield of corn, wheat, 

 and oats, althougli where this gi'owth is checked, as we fre(iuently see 

 from local causes. lari>e ci'ops can bo ])roduced in this State." 



The ap|)licatio!i of these principles to the growth and culture of 

 the cotton plant is discussed. 'I'wo periods in the growth of this 

 j'lant may be distinguishe(l. TJu' first extends from the time of 

 {)lanting. whicli in South Carolina is about the middle of A])ril. to 

 the middle of the sununei'. This is the time in which the ])lant makes 

 its growth of stalk' aiul foliage and gathers u]) iu)urishment to be later 

 transferred and stoi'ed np in the sihmI. During this ])eriod tropical 

 conditions are favorable, namely, moisture in the soil from frequent 

 rather than long-continued I'ain. high temperature with small daily 

 variation, plenty of sunshine, little wind, and a high relative htunid- 

 iiV of the atmosi)here to reduce e\aporation to a minimum. During 



