CONSTRUCTION OF HOT-BEDS. 75 



plunge a thermometer in the bed, and when the heat begins 

 to decline from 100 degrees, then operations may be 

 begun with safety. But for Avhatever purpose a hot-bed 

 is used, in all such latitudes as New York, the beds should 

 never be made before the first week in March ; great risk 

 is run if they are made much sooner, with but little ad- 

 vantage in earliness. Greater caution is necessary in air- 

 ing than with the cold frame, for with the hot-bed the 

 heat from the manure, together with that of the sun's 

 rays, will often, in an hour, run the temperature so higli 

 as to destroy its entire contents, if airing at the proper 

 time has been neglected. Many a merchant, doing busi- 

 ness in the city, has gone home in the evening to his 

 country residence to find that his hot-bed, that had been 

 his pride in the morning, had become a scorched brown 

 mass at night for want of attention to the safety-valve of 

 "airing." In such cases, when no competent person is 

 in charge, the safest way is to tilt the sashes a few inches, 

 even before the necessity arises, rather than run the risk 

 of the sun coming out strong, and destroying the whole. 

 In a southern exposure, in a sheltered place, there is 

 rarely clanger in admitting air in most days in March or 

 April from nine to four o'clock. But, of course, judg- 

 ment must be used in extreme cases. The greater heat 

 in the hot-beds necessitates watering freely whenever the 

 surface of the soil appears dry, which, in dry weather, if 

 the heat is strong, will usually be every other day. In 

 the absence of sashes, the "protecting cloth " alluded to 

 in the chapter on cold frames, can be used to cover the 

 hot-bed. Its use is safer than that of glass sashes, for the 

 bed does not heat up as if covered by sashes in fact, there 

 is no necessity of ventilating at all, if covered by the 

 "cloth sashes," although in mild days they should be 

 taken of! altogether to admit the light to che plants, but 

 protecting cloth should not be used on the hot-beds 

 sooner than the middle of March. 



