408 Cultivation of the Vine. 



weather be clear, until the first leaves of the vines are fully 

 expanded ; when the temperature may be kept between 85° 

 and 90° in the day time, in clear weather. When the vines 

 are in flower, I keep the temperature between 55° and 60° 

 in the morning; and between 65° and 70° during the day, if 

 dull weather, and about 85°, if sunshine. After the grapes 

 are set, the thermometer may be allowed to rise to 90° or 95° 

 during the day, in clear weather. In dull or wet weather, 

 in summer, instead of kindling fires at night in the ordinary way, 

 I cause the flues to be heated in the morning, in order to raise the 

 mercury in the thermometer to about 70° during the day; and 

 allow the fire to burn out towards night. The temperature, in 

 the day time, from the commencement of forcing, should be regu- 

 lated, in some measure, by the heat of the vine-house during the 

 night. For example, if the house has been colder during the night 

 than I could wish, I keep up a greater heat than usual during 

 the following day; and, if it has been warmer during the night, 

 than I consider requisite, I give less fire during the day than 

 usual ; or more air, according to the state of the weather. In 

 order to have the young wood sufficiently ripened, if there is any 

 appearance of frost at night, towards the end of autumn, I cause 

 a small fire to be kindled just sufficient to keep the frost out of 

 the house. This is continued, when the nights are frosty, until 

 the leaves are all down. As regards exposure of the vines in 

 winter, I had my vine houses shut all last winter, as I see no use 

 in exposing the vines in winter. 



Many may object to the lowness of the temperature that I have 

 recommended during the night, when the grapes are in flower; 

 but all the kinds cultivated here, including the Tokay, black Ham- 

 burg, white Sweetwater, &c, uniformly set well with the heat 

 above-mentioned. Indeed, when the nights have been frosty 

 during the time my vines were in flower, I have seen the ther- 

 mometer as low as 52° in the morning ; and I never observed 

 that they sustained the least injury by this low temperature. 

 Too much dependence has hitherto been placed on the influence 

 of fire heat in the forcing of hot-houses. The great art is to do 

 with as little fire heat as possible; and to take the utmost ad- 

 vantage of the heat derivable from the sun's rays, consistent with 

 giving a sufficient quantity of air. The legitimate use of fire 

 heat is to prevent the bad effects of frosts, snows, and inclement 

 weather. 



I may now say a few words on giving air. In clear weather 

 it should always be given early in the morning, and taken away 

 early in the afternoon. For example, let a small portion of air 

 be given between eight and nine o'clock in the morning, and if 

 the day continue clear, give more between ten and eleven, and 

 take it all away at three o'clock. I seldom let air into my vine- 



