1S73.] TEMPERATURE OE FORCING-HOUSES. 155 



tinent and some Eastern countries, the sun is more powerful by day, 

 and radiation more excessive by night, we may conclude that the daily 

 range is much greater, only, being more constant, vegetation will get 

 inured to the conditions in the same way that Yines will bear a bright 

 sun if it is steady, under which they would flag after a period of dull 

 weather. 



This is the kind of information "D. J." seems to be craving for, 

 and it is to be hoped the above will satisfy him to some extent. I 

 think, at least, the above facts will show that, in recommending a 

 minimum temperature of 50° for Yines (in the early stages of forcing) 

 after a high day temperature, rather than trust to hard firing to no 

 purpose, I have kept within safe limits. 



I can see no reasons, physiological or other, for thinking that 

 Yines, up till the setting period we shall say, can be injured in any 

 way whatever by allowing the temperature to fall to 50° or 45° before 

 morning after a bright sunny day and a high day temperature. This 

 is my argument, and I shall gladly listen to any facts " D. J." or any 

 one else may advance to the contrary ; but they must be conclusive. 



I have seen the thermometer in a long Peach-case once under my 

 charge run up to 90° and 100° during the sunny days of April and 

 May, and fall to 45° or 40° before morning, and this would go on for 

 days : there was only 2 feet of space for ventilation altogether. Yet 

 the crops of Peaches and Plums were always excellent, and are to this 

 day. It is my regular practice here to run up our early Peach-house 

 to 85° or 90° in sunny weather before the fruit is stoned, rather than 

 admit heavy draughts of cold air, and I am perfectly satisfied on such 

 occasions if the thermometer stands at 40° in the morning. I have, 

 of course, no objections to a high night temperature comparatively, if 

 it can be secured without much fire-heat. Our early Yinery is allowed 

 to fall to 50° or 55° before sunrise in clear frosty weather up till the 

 setting- time ; and our maximum night temperature for jMuscats is 65°, 

 often falling to G0° before morning. In mild dull weather this 

 practice is, of course, modified considerably : the temperature is neither 

 so high by day nor so low at night. My only objection to a low 

 night temperature is the time lost in getting up the heat in the fore- 

 noon in dull days, so as to have heat with light, when there are, 

 perhaps, 700 or 800 feet of piping attached to one boiler. In a glass 

 case here, devoted to Hamburgs and Peaches, we had at one time a 

 Muscat Yine which invariably set well and equally, though it rarely 

 had a night temperature above G0°, often not so high, while setting, 

 unless the weather was mild, for there was not piping enough in 

 the house to keep up a higher figure when the outdoor temperature 

 was low, but we made the very most of the sunshine during the day. 



