58 MISSOURI BOTANICAL GARDEN BULLETIN 
SOME PRACTICAL OBSERVATIONS ON ENDS 
AND WALLS 
It is quite evident to those of you who have been employed 
in greenhouses what is meant by ends and walls, but their 
importance is often overlooked. It has been the experience 
of the writer to pass through an unusually severe winter 
which offered the chance of seeing the benefits of things 
done and the unpleasant results of things undone in this 
regard —in other words, to see the advantages of pre- 
paredness. 
Greenhouse ends, as they are usually found on the aver- 
age commercial establishment, are the weakest part of the 
structure, especially on the older places. It seems as though 
they had been the last and least-considered part of the house 
during its erection. Even on newer structures an extremely 
well-braced end is seldom found, unless it is a specially de- 
signed house, and less often do we find them with double 
glass gables. 
It has been an opportunity to observe during the season 
just past the ends on six greenhouses, all having a western 
exposure. Four of these houses were fitted with single glass, 
as is the common thing, and two with double glass. On 
very cold days, when it was 25° below zero or there- 
abouts, the single glass was coated with a heavy layer of 
frost and the only means of looking outside was through 
the ends which had the double glass. The two types 
showed a great variation in temperature, the double glass 
ends being much warmer and showing a greater tendency 
towards uniformity and freeness from draughts. The exact 
records of the different temperatures were not kept because 
the facts were so obvious that our course on greenhouse end 
for the future was immediately decided upon. However, it 
would be interesting to work out the differences in tempera- 
tures and also the effect upon the strength of the wall in 
houses with and without the double glass ends. 
As was the case with the ends, our observations showed 
that the greenhouse walls were too thin for severe spells of 
cold weather. They are usually either built of single thick- 
ness with a building paper or a cement coat, or of double 
boards with ig between, but seldom with an air space. 
The neglect here is perhaps due to the fact that the early 
greenhouses were glass-covered dug-outs and required no 
material for walls; and as they were gradually built more 
out of, and finally on top of, the ground, the tendency was 
to think that the walls were still of mnales consideration. 
In our greenhouse frost has killed chrysanthemum plants 
