66 PRACTICAL FLORIcrLTUr.E. 



measuring about 7,000 square feet of glass, are copiously 

 drenched with water in one hour. If watered in the usual 

 way by watering-pots, the same number of hands would 

 not do the work as well in six hours. 



Of all labor-saving apparatuses yet introduced into our 

 gardens, this force pump is the most valued. 



As a green-house of this description is built for the pur- 

 pose of growing winter flowers, ample provision is made 

 for heating ; eight 4-inch pipes run its entire length, which 

 is about one square foot of heating surface to three square 

 feet of glass, or, in other words, one foot of 4-inch pipe to 

 three square feet of glass. This is the necessary quantity 

 when a night temperature of 60 degrees is required in sec- 

 tions where the thermometer runs down to 10 or 15 be- 

 low zero. "When a temperature of 40 or 45 only is 

 necessary at night, one foot of heating surface to four feet 

 of glass is the rule. But, of course, much depends on ex- 

 posure, style of green-house, etc., so that no infallible 

 rule can be applied. 



CHAPTER XI. 



GBEEN-HOUSES ATTACHED TO DWELLINGS. 



Every now and then the inquiry is made : " How can I 

 best attach a green-house to my dwelling?" Nothing is 

 more simple, as far as the mere shell of the green-house is 

 concerned, but the difficulty is to heat it. Many may not 

 know that a screen-house, even without any artificial 

 means of heating, can be made very useful in the early 

 spring months in this latitude, and in those Southern 

 States where the thermometer does not fall lower than 20 

 or 25. It may be used all through the winter. 



