APRIL. 
109 
consider it a great auxiliary, and also for very late Grapes, particularly 
Muscats, for we should remember that inside borders, during the sum¬ 
mer months, are by no means so favourably situated as those outside 
for absorbing and retaining the heat, as these latter face the south, and 
generally slope to a favourable angle for receiving the whole influence of 
the sun’s rays; on these grounds I would lay hot-water pipes under all 
inside borders for Grapes, to be used for imparting warmth, or not, as 
circumstances required. 
We have, then, 4000 feet of piping, for supplying top and bottom heat 
to a block house 100 feet square. From this it will be obvious that a 
good saddle boiler will be powerful enough to heat the whole. I do not 
allude here to the merits (and I understand they are great), of the 
tubular boilers invented by Mr. Weeks and Mr. Ormson, nor yet to 
Mr. Thompson’s retort boiler ; my object is to show that there would 
be no difficulty in heating a block double the size I name by a single 
boiler, as the distance which the pipes would have to be carried from 
the boiler, and the number of feet laid down, would not equal what 
single boilers are heating at this present time; and in no case of heating 
a block house, would the pipes have to be carried out of the house, which 
in heating separate ranges, or houses, must always be the case ; and 
however securely they are packed in non-conducting materials, waste of 
heat, to somr extent, will take place. Taking the four divisions we have 
sketched out in our block, let the two farthest from the boiler be the 
latest or successional houses, and by an arrangement of the pipes 
passing through the divisions nearest the boiler, readily comprehended 
by an engineer, not a particle of heat need be lost. Whatever the size 
of the block, it will assist the after management if three sides only of 
the building are of glass, and the fourth a wall, on which side the boiler 
should be placed, as near the centre as possible. Sheds for potting and 
fuel could also be arranged right and left of the boiler, with admissions 
into the divisions for the workmen to attend to the culture of the crops. 
I have supposed the border to be confined to the floor of the house, 
but in some cases it may be necessary to have a border running round 
the outside of the building, eight or ten feet wide; when this is adopted 
the outer foundation walls should be arched, or the parapet wall should 
rest on girders supported by piers, which I prefer, as allowing more 
room for the roots of the trees inside to pass outwards. Although somewhat 
irrelevant to the subject of construction, I may add that the borders, where 
inside and with pipes underneath, may range from three to four feet in 
depth; but I strongly advise for Vinery borders that one-third of the whole 
compost should consist of rubble stones broken into two or three sizes, 
or brickbats, to which may be added charred wood and one-inch bone- 
dust. As the supply of water is entirely under control, no fear need be 
entertained of the borders getting too wet; and being made in conse¬ 
quence of this deeper than usual, they will serve to maintain the Vines 
in a state of luxuriant growth for a long period. 
The ventilation of block houses requires some consideration. In the 
first place the six-feet upright glass on three sides will have double 
sliding sashes, to run up and down ; the cross-walls forming the 
divisions will also be of glass, resting on walls the same height as the 
