Greeshoi.'se Construction. 15 



To erect the roof commence at one end of the build- 

 ing, raise one length of the ridge, putting bars on 

 either side at each end, fasten those at the end of the 

 bvrilding permanently, the others temporarily, so that 

 should your ridge not be straight, it can be lowered or 

 raised as you proceed to place the bars in position. 

 When using a continuous ventilator let one-third of 

 the bars run to the roof — and these should be put up 

 first — in doing which use a gauge sufficiently long to 

 allow for three rows of glass with their short bars 

 between. 



As soon as one section of ridge is complete, plumb it 

 by drawing a line from plate to plate at the base of the 

 first set of bars, dropping a plumb line from the top of 

 the same bar and vary until the lines touch. Brace se- 

 curely and proceed to erect in the same manner the rest 

 of the roof. After setting the long bars have some head- 



Fig. 11. 

 ers prepared (Fig. 11), of suitable length and thickness 

 to fill in between them, for the support of the shorter 

 bars on the same side, and if the upper surface of this 

 header is as wide as can be made from two inch stock 

 it will serve to hinge the ventilators on if they are to 

 open at the top. With a short gauge (See Fig. 12), 

 set your shorter bars. Fill in between these, where 



