16 PRESENT-DAY GARDENING 
is convenient to remove the tiles and restore the natural 
earth surface. In arranging the staging, one essential 
object has to be kept in view, namely, that no part of 
it shall be out of easy reach; for very wide stages are apt 
to cause the plants in the back rows to suffer neglect. 
METHOD OF HEATING 
In these progressive times it is not well to lay down hard- 
and-fast rules with regard to the best type of appliance. It 
should, however, be urged that every Orchid house ought 
to be heated with hot water, and, that in all cases 4-inch 
piping should be used, the radiation of heat from that size 
being much more gentle and equal than from smaller pipes. 
Bottom heat by means of piping under closed-in beds of 
cocoa-nut fibre, or any other material, is bad, although, in a 
very slight degree, some arrangement of the kind may be 
of assistance in the house devoted to raising seedlings. If 
it is used, an outlet must be provided for the inevitable 
moisture thus raised so that it will not condense and fall 
on the plants. 
For small houses or blocks of houses, the old saddle 
boiler in some form is all that can be desired ; and there 
are several forms of slow-combustion boilers which may be 
set almost on the surface of the ground outside the house, 
and these are satisfactory. For blocks of houses the English 
form of sectional boiler is one of the very best; in large 
blocks duplicate sets of this pattern, or any other type that 
may be selected, should be set down, as it provides means 
of heating the houses if the ordinary boiler happens to fail. 
It is always better to provide more power than may appear 
