8 THE amateur's geeenhouse 



and walk sunk below the level, the back wall of which was 

 built of old floor-boards placed double, and filled in between 

 with sawdust. 



A number of minor improvements have been adopted of late 

 years in the construction of plant houses, the effect of which 

 has been to cheapen them considerably, without impairing, 

 and in some instances actually improving, their efficiency. 

 We say nothing now of patented ventilators and such like, 

 for it occurs to us to mention, first of all, that heavy rafters 

 and sliding lights have become almost obsolete. It is found 

 that side ventilators are in many instances sufficient; but 

 where roof ventilation is required in addition it may be ob- 

 tained in a much cheaper and more simple way than by the 

 adoption of sliding sashes. Separate squares of glass may be 

 hung on hinges, or narrow-hinged lights may be inserted 

 at intervals. The disuse of heavy rafters, in consequence of 

 their being no longer required to carry sliding lights, allows 

 of the use, throughout, of light sash-bars, carrying larger 

 glass than was ever used for the purpose until within the past 

 few years. Thus a more complete flood of light is obtained 

 than was possible in the old-fashioned houses, while the ven- 

 tilation is more perfect and far less cumbrous. As for the glass, 

 it should be good English, weighing twenty-one ounces to the 

 square foot. The low-priced Belgian glass is quite unfit for a 

 plant house, however well it may be adapted for sheds and 

 workshops ; its numerous specks and bubbles act as burning 

 glasses on the leaves beneath them, and the result is brown 

 spots, holes, and other disfigurements. 



There will still arise, perhaps, in the mind of the amateur a 

 number of questions as to the particulars of the construction 

 of the house required. The proper angle of the roof may be 

 one of them, and that is by no means a matter of trifling im- 

 port. Por all general purposes the flatter tlie roof the better, 

 because it will conduce to the short healthy growth of the 

 plants, if they are placed as near the glass as possible ; but 

 there are two serious objections to the adoption of a low angle. 

 It incurs a liability to drip, and it provides a playground for 

 cats in a district where those interesting quadrupeds abound. 

 We once suflered in a frightful manner through the breaking of 

 a pane of glass on a low-roofed house when a party of cats 

 were holding an out-door nocturnal demonstration upon it. 

 They fell in and went mad with fright, and committed such 



