THE CONSTRUCTION OF PLANT HOUSES. 93 



market, cannot now be had. The choicest grades and highest cost 

 white pine lumber which can now be obtained contains a large 

 proportion of white, or what is known in the trade as " bright", 

 sap. The medium and lower grades contain still more of it 

 besides other imperfections. It has become impracticable to 

 obtain white pine of the same quality as formerly used. Long 

 leaf yellow pine also has advantages and is well adapted for 

 florists' houses and for plant beds, as it is strong and durable ; 

 but, as it does not hold paint well, it is not suitable for conserva- 

 tories and greenhouses which require nicely finished work. Owing 

 to this fact, builders who desired to keep up the standard of their 

 work, looked about for a substitute, which was found in C3q3ress. 

 It has not only proved itself a substitute, but in the qualities most 

 necessary for greenhouse work it is far superior to pine. It is 

 more lasting. Examples are numerous of shingle roofs which 

 were put on more than a hundred years ago — three or four times 

 the age which the best pine shingles are expected to last. Cypress 

 is used extensively in the South for posts on which dwellings are 

 supported, fence posts, and railroad ties, and for all purposes 

 where the wood comes in contact with the ground ; and in the 

 North it has been used for years for water tanks and gutters. Its 

 durability for such uses is on a par with red cedar or locust. The 

 best quality is known as red cypress and comes from the Gulf 

 States. It should not be kiln dried. After it is perfectly air 

 dried and ready for use, it shrinks less when exposed to heat and 

 swells less when exposed to moisture than any other known wood. 

 For these reasons it holds paint better than white pine, and these 

 qualities peculiarly fit it for use in greenhouse construction. 



Heating. — There are but two systems of heating which are 

 generally approved for greenhouse purposes, viz., steam and 

 hot water. In conservatories and greenhouses of ordinary dimen- 

 sions for private use and which are not sufficiently important to 

 require a night attendant, hot water has advantages and should be 

 adopted, and with the ordinary attention given to its regulation 

 and radiation, pipes of four inches external diameter will be found 

 the most satisfactor3^ For large ranges of glass, consisting of 

 say ten thousand feet or more, steam has advantages and should, 

 under ordinary circumstances, be adopted. 



Foundations. — Stonework, showing above grade from two to 

 four feet, forms the handsomest foundation for a glass building in 



