Dec] the HOT-HOUSE. 59 J, 
to check the piercing wind. If there are short roof- lights, they 
must be covered with mats, or with strong canvass, during the con- 
tinuance of severe weather; these may be so contrived as to roll up 
and fall down, by means of lines and puUies, at pleasure. 
During the continuance of severe frost, accompanied by piercing 
cutting winds, the windows must never be opened, that is, you must 
neither slide the lights up or down, but always keep them and the 
door or doors close; and any plants that are too near the glass must 
be removed into the interior of the house, especially at night and in 
cloudy dark weather. 
If you find the frost likely to reach your plants, notwithstanding 
all this care, you must heat the flues by gentle fires at night, and 
also in the day time when the frost is very piercing and the weather 
dark, and indeed without such a convenience it is almost useless 
to attempt the erection or trouble of a green-house either in the 
middle or eastern states, on account of their extremely rigorous 
winters. But you must be particular never to heat the air above 
40 or 45 degrees of Fahrenheit's thermometer; for all the heat that 
the plants require at this season, is only just as much as will pre- 
serve them effectually from frost. 
However, be very particular every day, when the weather is mild 
and the sun shining on the windows, to slide down the sashes, even 
if but half an hour, in the middle of the day, to admit fresh air and 
ventilate the house; for if the plants are kept too close they will 
become tender and weak, and besides, it will cause the leaves of 
some kinds to turn ofa yellowish sickly colour, and afterwards to get 
mouldy and drop off. 
N. B. The plants must never be deprived of light by keeping 
the shutters closed a moment longer than it is found absolutely ne- 
cessary for their preservation; and though I am not an advocate for 
much fire-heat in a green-house, yet I would prefer it to keeping 
the plants too long in darkness, which has an extremely bad effect 
upon them. 
For particulars respecting watering and other information, I 
would recommend to your perusal at this term, the entire of the 
article green-house, in January, and also in February, pages 85 
and 165; the general care during each of these months is nearly 
the same. 
The plants which you are wintering in garden-frames, must now 
be carefully attended, agreeably to the directions given in page 572. 
THE HOT-HOUSE. 
The frost generally sets in very severe in this month, and the 
winds are keen and cutting; therefore it will be necessary to keep 
up your fire heat in proportion to the severity of the weather, which 
