80 THE PRINCIPLES OF FLORICULTURE 



The second row of glass should be placed entirely across 

 the roof, so that the sash-bars will again be properly 

 spaced, and this second row is held in place with brads 

 the same as the first row. In laying this second row, care 

 should be taken to have the bevel of glass the same as 

 before, otherwise there will be quite a space between the 

 two panes of glass, admitting much air and water. Row 

 after row of glass is laid, and outside or inside stagings are 

 built to facilitate the work as it progresses towards the 

 ventilators or the ridge. 



In estimating the width of the roof, care should be taken 

 that it be just wide enough to take whole panes of glass. 

 This avoids the cutting of panes at the ventilator or the 

 ridge, which means a saving of both time and glass. If it 

 is not possible to have the roof of the right width to ac- 

 commodate a full pane of glass, it should be of such a width 

 that a half pane may be used. In handling the glass, 

 great care should be taken to keep it clean, and especially 

 free from putty, the marks of which are difficult to re- 

 move, and if not removed, it detracts from the amount 

 of light admitted. 



After the roof is glazed, all surplus putty is scraped off. 

 In removing putty, it is important that the pressure of 

 the putty knife be brought against the space between the 

 glass and sash-bars. In this way all spaces are filled. 

 After the putty is removed, the glass is cleaned and the 

 sash-bars are ready for painting. 



Painting the roof. In painting the roof, all exposed 

 areas of putty should be covered. All sash-bars should 

 have a priming coat of thin paint before the putty is laid, 

 otherwise the oil from the putty will enter the wood, 

 causing the putty to crumble and the glass to loosen. 

 This crumbling also occurs if the putty is not carefully 



