194 THE ORCHID REVIEW. [JULY, IgI0. 
The door opens directly into the house, and I often wish that I had 
built a small glazed porch with a second door to lessen the inrush of cold 
air when entering the house in winter. 
I use a small horseshoe boiler (nominal heating power r5oft. 4in. piping) 
built into the wall of the house, and about rooft. of 4in. piping in three 
rows; this is equivalent to 45’5ft. of piping per 1,000 cubic feet of house, 
barely enough for my purposes ; 130ft. or 6oft. of piping per 1,000 cubic feet, 
and a rather larger boiler would have been better. This may seem a large 
amount of piping, but it must be remembered that a small house has a 
greater surface in proportion to cubic capacity, and can therefore lose heat 
more rapidly than a large house, just as a child loses heat more rapidly than 
an adult. 
The boiler must have a nominal capacity considerably greater than. the 
amount of piping it has to supply. I find that the larger the boiler, within 
limits, the easier it is to keep the temperature steadily at the point desired, 
whether high or low. With my present boiler I can keep the temperature 
of the pipes at 95°-100° F. without the fire going out. With a larger one 
and more piping I could, if necessary, keep the pipe temperature still lower. 
Of course in larger installations there are means of shutting off pipe heat 
from a house, but I do not understand that these are applied to small single 
houses. I believe it would be possible to devise a cheap and simple system 
for a small house by which pipe heat could be shut off without letting the 
fire go out, and such a system would be of considerable value. 
I have adopted Mr. O. O. Wrigley’s admirable plan of using thermo- 
meters to measure the heat of the pipes (see O. R., vol. iii. p. 87). To avoid 
the expense of fitting the thermometer to the pipes I fixed a metal tub2 of 
1in. diameter in the lid of the expansion box. This tube rises to the level 
of the upper surface of the stage, so that its opening is readily accessible. A 
chemical thermometer fixed by perforated corks in a tube of Sin. diameter is 
lowered into the tube in the expansion box to such a point that the bulb is 
between the openings of the flow and return pipes. The tube containing 
the thermometer is corked at its lower end, and a portion of the side opposite 
70°-180° F. on the thermometer is cut away so that the thermometer may 
beread. The bottom of the tube must be corked so that when the thermo- 
meter is lifted it brings enough hot water with it to keep the mercury from 
falling while an observation is being taken. The thermometer should be 
kept in the expansion box. After a year or two it may become inaccurate, 
but it can be replaced cheaply. The whole apparatus as I made it need not 
cost more than 2s. 6d. A cheaper form still can be constructed by passing 
a chemical thermometer through a hole in the cork of a small, wide-mouthed 
bottle and suspending the latter by a wire hook in the expansion box. The 
cork in the bottle should be perforated in several places to allow free ingress 
