GREEN-HOUSE STRUCTURES. 113 



are not able to judge of the dangers resulting from wood- 

 work being in close contact with the heated bricks. (For 

 cost of construction see page 116.) 



HEATING BY STEAM. 



Steam heating, we think, in all probability will soon be 

 extensively used, particularly in large establishments that 

 are put up at one time. The following is from E. H. 

 Bochman, Pittsburgh, Penn., who has been eminently 

 successful with steam heating for green-houses. He is 

 strong in the belief that it will eventually supersede all 

 other methods. He says : 



" The New System of Heating Green-houses by Low- 

 pressure Steam, by which are gained important advan- 

 tages in every essential requisite in a heating apparatus, 

 viz., efficiency, economy of fuel and attention, safety, and 

 simplicity, consists of a series of steam tubes of not less 

 than two inches in diameter, placed under the benches or 

 suspended along the walls, as may be best suited, in such 

 a manner as to drain themselves into a water and steam- 

 tight vessel, which, therefore, has to be situated at the 

 lowest convenient point. These tubes or pipes should 

 present a radiating surface of about one square foot to 

 ten square feet of glass surface ; or, better expressed, one 

 square foot to seventy cubic feet of space to be heated to 

 at least 55 in any weather up, or rather down to 25 

 below zero, and at a pressure of steam not to exceed fif- 

 teen pounds to the square inch. If a higher temperature 

 is desired, say from 65 to 70, make the radiating surface 

 equal, say, one square foot to fifty cubic feet for the same 

 pressure of steam. The form of boiler is immaterial ; 

 whichever is best suited and most economical for the 

 particular fuel you use, is the one to adopt, and its ca- 



