THE AMATEUR’S KITCHEN GARDEN. 173 
a hot-water tank. Although both cucumbers and melons 
may be grown to a high state of perfection upon rubble, it is 
not equal to a tank, the heat from which causes a moist atmos- 
phere. The heat from a tank is also more sure and lasting. 
In any case where it is desirable to have a tank, it can be 
substituted in either of these sections in the place of rubble. 
The best form of tank for the purpose is constructed of slate, 
and partially filled with water, through which passes a flow 
and return hot-water pipe as explained above. In every case 
as much as 18 inches of soil must be provided ; two feet is ' 
not too much as spring advances. The best materials for 
rubble are flints or brick-bats, two feet in depth, with a cover- 
ing of coarse washed gravel, or some newly cut turves laid 
grass downwards. After the rubble is in its place, and as the 
soil is added to it, place some drain pipes three feet apart along 
the middle of the bed ; let one end of them go down to the 
rubble, and the other end just above the surface of the soil. 
These are to be the conductors of water into the rubble below 
when a strong heat is necessary. To every twelve feet length 
of bed about four gallons of water must be used every other 
day; this must be poured down the drain tiles, to moisten 
the rubble, etc., below. 
As regards the amount of piping, the small circles show no 
more than is actually necessary. If, in fact, no more is added 
than in the positions shown, there will be no extra amount of 
heating surface to fall back upon in case of severe weather in 
mid-winter. It would be well therefore to add, besides those 
shown, two more pipes in each case for top heat, to be used 
when wanted, and full control should be secured over the 
whole of them by valves to shut off and turn on at pleasure. 
This is assuming that 4-inch pipes will be used. If a size less 
is used — say 3-inch, then there ought to be more of them, 
that the heat may be mild and continuous. If only the same 
quantity of 3-inch pipes are used as shown in the diagrams, 
then it would be necessary in severe weather to make them so 
hot, to keep up the required degree of temperature, that the 
heat given off would be positively injurious even with the 
precaution of using evaporating pans upon the pipes. 
A Pit for Winter Cucumbers will serve as well as a house 
where only a small supply of fruit is required. It should if 
possible be sunk below the level to economise heat, and a tank 
is very much to be desired ; but a good make-shift structure 
