56 MASSACHUSETTS HORTICULTURAL SOCIETY. 



about one-third of the coal is wasted in a dull fire, and if this 

 waste is enough to pay a night man and something more then it 

 will pay to hire him. This is not generally understood, it being a 

 common mistake to think that a dull fire is economical of coal, 

 while the reverse is true. In large establishments there is another 

 advantage in having a good watchman. Our climate is extremely 

 treacherous and it is not easy to leave the greenhouse for six 

 hours so that it shall carry the uniform temperature required by 

 delicate plants when the outside temperature may change twenty 

 degrees without warning, so that where perfect work is to be 

 done the steam boiler and night watchman are essential and 

 economical. 



The number of steam pipes required to maintain a temperature 

 of 40° in severe weather is found by allowing one inch in diameter 

 of pipes for each three feet of width of the house measured on 

 the rafters. Thus a house whose rafters measure twenty-four 

 feet will require pipes whose aggregate diameter is eight inches to 

 keep a temperature of forty degrees. To maintain a temperature 

 of 50° will require about twice as much pipe as 40°, and 60° about 

 three times as much. Of course exposure to the wind will have 

 much to do with the ease of heating a house ; in exposed situations 

 nearl}- double the pipe is needed. Where hot water circulation, 

 not under pressure, is used, it will require about double the pipe 

 to do the work that is needed for steam or water under pressure. 



"Watering under glass in winter is best done in the morning of 

 a clear day, so that the leaves may dry off by airing the house. 

 In spring or summer the afternoon is a better time, since the 

 water then soaks in better. Water for tender tropical plants, such 

 as cucumbers, should be of about the same temperature as the 

 house and may be conveniently heated by a coil of pipe in the 

 chimney. 



Shading greenhouses is necessar}' in spring and summer, and 

 for this purpose a mixture of glue and whiting, or of white lead 

 and naptha is good. Lime injures the glass and putty. 



The internal arrangement of the greenhouse must depend upon 

 the purpose for which it is to be used. If for economy and profit, 

 the beds are built of hemlock or cypress boards held in place by 

 steam pipe driven into the ground. Beds raised from the ground 

 are built of slates on a frame of cypress. It is well to keep the 

 beds as near the glass as jou can so as to get all the light 

 possible. 



