THE AMATEUR’S KITCHEN GARDEN. 
241 
heat at little cost, hut because generally speaking better work 
may be done with their aid than with hot-water pipes. The 
last-named are however the surest, cleanest, safest of heat 
diffusers, and so far economical that market growers, who 
must make things pay, trust much more to hot water than to 
fermentation in all their more important winter work in the 
production of vegetables and flowers. The reader interested 
in this subject may be advised to turn to the chapters on 
frames and hot-beds, for the proper use of these is the first 
thing to be learned in the practice of forcing. The next 
phase of the business is that of the forcing- house proper, on 
which it now becomes our duty to speak in detail. 
A Forcing-house adapted for supplying early vegetables 
and flowers may with advantage be constructed in a span 
roofed form, and should be snug and compact, with no more 
headroom than is absolutely necessary for the work. The 
most useful and inexpensive structure for forcing small 
things, such as flowering plants, kidney beans, asparagus, and 
strawberries, is a span roof house seven feet high from the 
path to the apex, and from ten to twelve feet wide, inside 
measurement. The outer wall of a house of these dimensions, 
whether entirely above or partly below the surface, should be 
three feet high and support side lights eighteen inches high, 
upon which the lower ends of the rafters must rest. Side 
lights of a greater height are not desirable, because the diffi- 
culty of maintaining an equable temperature is increased in 
jiroportion to the increase in the surface of glass. To main- 
tain a temperature moderately uniform is of so much im- 
portance that some cultivators prefer houses without side-lights, 
but the additional light which finds its way into the house is 
of so much importance to the occupants during the short 
days that they are decidedly advantageous. It is not needful 
that they should be moveable, but as the houses can be turned 
to account in the cultivation of many things during the 
summer season, which are all the better for a free circulation 
of air amongst them, the little additional cost in fixing the 
lights so that they can be opened and shut at pleasure is not 
worth considering. The roof can be fixed, or lie formed with 
rafters and moveable sashes, but in either case the arrange- 
ments must be such as will allow of air being admitted, as 
required, near the apex. The walk must of necessity be 
down the centre of the house, and the width should be full 
