100 THE FORCING GARDEN. 
good single clip glazing will answer well (see figs. 7, 8, 
and 9), omitting the under glazing, although I would 
even recommend double glazing for them as a safe- 
guard against frost, and more economical as regards 
firing during the winter. Whenever a house for 
Camellias alone has to be unavoidably built facing the 
south with one roof only, 7.¢. a lean-to, it should be made 
pretty flat and glazed with green glass. In this case 
the bars may be 18 inches apart. If green glass can- 
not be had, I advise that a thin transparent green 
paint be used for a permanency ; for I find that plants 
do much better under green glass during the summer 
than under clear white glass: especially is this the 
case with Camellias. When, however, a house for these 
can be built with a span roof running north and south 
they will do much better than in a lean-to house. 
This house is 14 feet high in the centre, and 7 feet 
high at the eaves, with 3 feet of glass sashes and 4 feet 
of brickwork: this gives abundance of head room and 
elevation enough for large plants all round; 22 feet in 
width will give plenty of room for a row of pots next 
the walls all round where one flow and return 4-inch 
pipe should be placed. A double flow and return pipe 
will be necessary for a house of this capacity in the 
northern counties ; but one flow and return once round 
the house will be enough for the western counties. 
If, however, double glazing is adopted, one flow and 
return pipe will answer for the colder counties, and 
none at al will be required in the western counties. 
The pipes should run round close to the walls of the 
house ; but if a row of plants are planted out into a good 
peat border next the walls, where they would do well, 
and nailed on them, they would form a pretty feature, 
