STAGING, BEDS, ETC. 95 
span-roofed houses usually employed by market growers 
is on each side the central pathway, where, if there are 
standards here and there, they are easily supported by 
means of pieces of stout batten nailed across from the upper 
part of the standards to the inside of a rafter or sash-bar, 
as shown in the sketch (Fig. 70). Here they are not in the 
way, neither do they obstruct the light to any extent from 
the beds beneath, unless fixed very low, but as a rule the 
nearer they are to the glass the better, in reason, from Qin. 
to 12in. being a very suitable distance. In houses provided 
with strong cross-ties in the roof, whether of iron or wood, 
shelves are sometimes laid on these, over the central or 
side pathways, there also they do little or no harm, and 
accommodate a quantity of small stuff, but being overhead it is 
a rather troublesome matter to get at and water their contents. 
Shelves slung to the rafters are, however, by no means 
to be recommended, being not only very unsafe, but increasing 
the strain where there is already quite enough weight to 
be carried. In three-quarter span-roofed and lean-to houses 
the best places ior shelves are in front of the pathway, 
close to the tops of the standards, and at the back, against 
or near the back wall. 
Shelves are sometimes fitted with a fillet tacked on both 
edges, and projecting 3in. or so above the upper surface 
on both sides—this is done to prevent the surplus water 
from the pots from dripping on to choice plants, etc., 
beneath, but in this case each should be given a gentle 
inclination towards one end ; or a groove may be run along 
each side, Zin. from the edge, with the same object. 
-3;Tanks,—Tanks of some description are almost indis- 
pensable in all well-appointed plant houses. Their object 
