Chap. XIX.] PllESEEVlNG GEAPES. 315 



possible period, must take care not to afford them too much heat, 

 as an excess of this, no matter how dry the structure may be, or 

 how favourably treated otherwise, is sure to cause them to shrivel 

 more or less prematurely. Give only just such warmth to the 

 pipes or flues as will insure sufficient buoyancy to any humidity (!) 

 which may arise in the house as to enable it to make its escape. 

 Independently of the ill effects caused by actual heat, a too-warm 

 atmosj^here, even in the driest house, will cause a correspondingly 

 excessive evaporation and consequent condensation." Then of 

 course we must have fire-heat and give air when foggy days occur, 

 " as," says Mr. Thompson of Chiswick — " the mean temperature 

 of this month (November) is on the average little above 40 ', and 

 the air is generally saturated wuth moisture. When this is the 

 case, moisture will be deposited on all substances exposed to the 

 air, if they are not warmer than it is. Grapes that are ripe 

 sliould therefore be kept warmer than the air, otherwise they will 

 be liable to damp. The application of fire-heat would effect this : 

 but if it were applied suddenly, and without air being given at the 

 same time, the heated air would deposit moisture on the berries ; 

 for although these would ultimately acquire the same temperature 

 as that of the air surrounding them, yet for a time they would be 

 colder, and so long as this is the case they would act as condensers 

 of the moisture in the warmer air in contact with them. The 

 more rapidly the air is heated, the greater for a time will be the 

 difference between the temperature of the fruit and that of the air, 

 and of course the slower the heating the less at any time will be 

 the difference. Give therefore, in damp weather, a little fire-heat 

 in the morning, and admit air. If the nights are cold, the tempe- 

 rature of the house should not be allowed to fall lower than 45^" 

 Here then are delicate operations and much trouble to bestow on 

 perhaps half a dozen houses during the winter months. If the 

 vineries are old and badly heated, the task is most difficult ; in the 

 best-constructed ones it is a great and needless labour. The 

 trouble of regulating the atmosphere, the expense for fire-heat, 

 and the necessity of keeping the house almost entirely devoted to 

 the Grapes, must render any improvement acceptable. 



M. Eose-Charmeux's method of keeping Grapes fresh and plump 

 throughout the winter by inserting the ends of their stalks in 

 bottles of water instead of letting them hang on the Vines for 



