108 GREENHOUSE CONSTRUCTION AND HEATING. 
end. Such a trellis is at once very light, strong, and 
practically imperishable, and if the bars are coloured 
pale blue or green, they really improve the appearance 
of the house. 
For vines, the wires ought to be fixed 15in. to 18in. from 
the glass, at least ; somewhat less, say 12in. to 14in., will 
answer well for cucumbers, while tomatoes may be trained 
still nearer to the glass, but not less than Qin. or 10in. in 
any case. When the trellis is too close to the glass there 
is always great danger of the foliage becoming scorched 
or ‘‘scalded ”’ under a powerful sun, while the leaves of both 
vines and cucumbers are also apt to get flattened against 
the glass, when they scorch, decay, and stick to the latter, 
obstructing the light and creating a very unsightly 
appearance, as well as crippling the functions of the 
plants. 
Pathways.—In most market and trade nurseries the 
walks or pathways usually consist of the natural earth, 
with a few barrows of fine gravel or ashes put down, more 
being added from time to time wherever a hollow place 
occurs and causes water to lie. A good layer of ashes 
make a nice, firm, and fairly clean walk, but the walk 
should be kept high in the middle, so as to throw off 
any superfluous moisture, especially in stoves and other 
structures where much water is used. 
Sea-sand also makes a very nice, clean material for 
-. surfacing greenhouse paths, being soft and pleasant to 
the tread, but it should be kept just moist, so as to present 
a firm instead of a loose surface, and when employed in 
warm houses it is apt to become very hot, and burns or 
scalds the feet. 
