THE GARDEN :M A G A Z I N E 
November, 1916 
T28 
The type of house that will satisfy the majority of people and requiring only moderate heat. Tomatoes on the roof, 
some flowering plants and young stock of later outdoor gardening on the benches 
the water is vaporized and kept under pres- 
sure; whereas by the other method the water 
is circulated in its natural state, returning 
by force of gravity through the lower pipes. 
Ordinarily there is an e.xpansion tank elevated 
above all parts of the system, but connected 
with some low point, to prevent compression 
of the water and the creation of steam. 
tVHAT TO LOOK FOR IN A HEATER 
The various heaters made by the several 
reputable firms differ but slightly and any of 
them will give satisfaction. However, it is 
well to know how to distinguish a boiler that 
is most likely to give good results. 
1. The grate and fire areas should be cor- 
rectly correlated and arranged. The most 
efficient arrangement brings the fire surface at 
right angles to the fire itself. It is, of course, 
also desirable that the passage of the heat be 
as great as possible before it leaves the heating 
surfaces, so that the heat be not wasted. 
In general, the proportion given above of i sq. 
ft. grate, to 20 sq. ft. of fire surface is a good 
average to look for. 
2. The circulation in the boiler should be as 
short, as direct and as free from friction as 
possible. Some water tubes are arranged 
horizontally, others vertically, but the simpler 
the distribution, as long as it involves a close 
connection of the water surface to the heat, 
the better. 
3. The boiler should permit of easy clean- 
ing and care. Poor qualit\’ fuel invariably 
chokes up the flues and renders frequent 
cleaning imperative. Furthermore, when the 
fire must be tended several times a day, a 
convenient arrangement of doors, dampers, 
shaker-bars, etc., contributes greatly to the 
economy of energy and time in handling the 
furnace. 
4. 1 he possibility of leaks and breaks must 
be considered, and the easier a boiler can be 
repaired the more satisfactory it is. The most 
conv'enient types make use of short bolts, 
permitting the removal of single parts without 
disturbing the rest. The modern “sectional 
type” is about the last word in this sort of 
convenience. Besides, it makes possible the 
enlarging of a boiler unit by unit, in propor- 
tion to any increase in the size of the house. 
The matter of covering or insulating a boiler 
after it is set up is important also. .Asbestos 
cements are supplied by dealers, which can be 
made into a sort of paste and used to cover the 
entire heater. .A thick coating of such a pre- 
paration prevents a great loss of heat from the 
Erected as an attachment to the living-room, the greenhouse becomes a “ snow ” house, and for best results needs other houses to serve as " growing ” houses 
