CONSTRUCTION AND HEATING OF GLASS HOUSES. 57 



best for our work is red cypress — that which comes from the 

 Gulf States, it being of closer fibre, greater strength, elasticity^ 

 and durability, and, therefore, much to be preferred to the white 

 cypress of the Central States. Cypress absorbs water very easily, 

 and if well seasoned and air-dried gives it up freely without 

 detriment to the wood, but if kiln-dried the absorption of 

 moisture will be very excessive, and cause much trouble by warp- 

 ing, twisting, and undue swelling of the wood when wet. I would 

 strongly advise those contemplating the erection of their own 

 greenhouses, not to purchase cypress from their local lumbermen, 

 for cypress handled by them if not always, is, in almost every 

 instance, kiln-dried stock, as this is the only stock in demand by 

 the general building trade for interior finish. I would suggest 

 that you either buy from the producers, emphasizing very 

 positively that what you wish is air-dried and not kiln-dried stock, 

 or from some reputable firm of horticultural builders, who carry a 

 stock of sizes and grades best suited for the purposes in view. 



We do not know the durability of cypress under the conditions 

 found in greenhouse construction, but we do know that it lasts 

 much longer than any material heretofore used. 



Having satisfied ourselves as to the material, we will now pass 

 to the details to be used in the construction of the house under 

 consideration, which is generally known as a Sash-bar house. 

 The most serviceable size of posts for a greenhouse, say about 

 eighteen feet and six inches wide,. is two by five inches, and they 

 should be placed from four to four and a half feet apart; in 

 many cases they are placed from six to eight feet apart, with a 

 two by two-inch intermediate post, used centrally between these 

 main posts' to give stiffness and nailing facilities for the siding. 

 The posts should extend to a depth of from two and one-half 

 to three feet below the ground line, the depth depending on 

 the nature of the soil, and the latitude in which the houses are 

 being erected. The height will be governed by the purposes for 

 which the house is intended ; for ordinary greenhouse purposes, if 

 provided with glass below the eaves, either movable or stationary, 

 the height should be about four and one-half feet above the 

 ground, but if solid board sides are desired, as in the house under 

 consideration, the height of the posts need be only about four 

 feet, and that on the north side of a three-quarter span house 

 eight feet. These dimensions usually give ample height above the 



