110 



GREENHOUSES 



of the pane from slipping lengthwise, as well 

 as to hold it down in place. 



In lapped glazing only two double points 

 are used for each pane, that is, one at each 



Fig. 63. Glazing with double glazing points 



lower corner. The upper edge is kept in 

 place by the bottom of the pane above it. Ad- 

 ditional points are required for the lower- 

 most and topmost panes in each run, and as 

 some will be lost and destroyed, it is well to 



