84 



OBSERVATIONS OF HALES ON 



Influence 

 of sup- 

 pressed 

 evapora- 

 tion. 



on hop- 

 vines. 



Observa- 

 tions of 

 Hales on 

 the blight 

 in hops 



and on account of the loose position of the new- 

 turned earth, which touches the roots at first but in 

 few points/' 



HALES proves the influence of suppressed eva- 

 poration by the following observations on hop- 

 vines. 



" Now there being 1,000 hills in an acre of hop- 

 ground, and each hill having three poles, and each 

 pole three vines, the number of vines will be 9,000 ; 

 each of which imbibing four ounces, the sum of all 

 the ounces, imbibed in an acre in a twelve hours' 

 day, will be 36,000 ounces = 15,750,000 grains = 

 62,007 cubic inches, or 220 gallons ; which divided 

 by 6,272,640, the number of square inches in an acre, 

 it will be found, that the quantity of liquor perspired 

 by all the hop-vines, will be equal to an area of 

 liquor, as broad as an acre, and yjjy part of an inch 

 deep, besides what evaporated from the earth. And 

 this quantity of moisture in a kindly state of the air 

 is daily carried off in a sufficient quantity to keep 

 the hops in a healthy state ; but in a rainy moist 

 state of air, without a due mixture of dry weather, 

 too much moisture hovers about the hops, so as to 

 hinder in a good measure the kindly perspiration of 

 the leaves, whereby the stagnating sap corrupts, and 

 breeds mouldy fen, which often spoils vast quantities 

 of flourishing hop-grounds." 



" This was the case in the year 1723, when ten or 

 fourteen days' almost continual rains fell, about the 

 latter half of July, after four months' dry weather ; 



