20 



in which the dust, &c, can accumulate, or for the 

 deposit of moisture. By this means one cause of 

 considerahle breakage in frosty weather is entirely 

 avoided ; and if a pane of glass is accidentally broken, 

 as each pane is independent of the others, the frac- 

 ture does not extend beyond the single pane. The 

 whole is very firm and compact, and the glass is not 

 liable to shake out, as frequently occurs in opening 

 and shutting sashes. (Gard. Chron.) 



If lapping be permitted, its width should not ex- 

 ceed one-eighth of an inch, and the panes 

 should be acutely rhomboid, to throw the 

 condensed vapour down to the lower cor- 

 ner, and induce it to trickle down the bars 

 instead of dropping. It is very doubtful 

 whether it reduces the amount of mois- 

 ture taken between the laps by capillary 

 attraction. {Johnson's Mod. Gard. Diet. 

 617.) 



Instead of lapping, as glass is fractured during 

 frost, owing to moisture freezing between the laps of 

 the panes themselves, or between metal laps and the 

 glass, it is advisable, as before recommended, to do away 

 with all laps. The edges of the panes may be cut ac- 

 curately rectangular, and wetted with liquid putty 

 before being placed in contact, and the join resting 

 upon flat narrow bars of iron passing the whole 

 length of the house. The bars across the breadth of 



