23 
No. 9. APRIL, 1901. 
SUNSHINE FOR 1900. 
BY L. G. CARPENTER. 
While the pleasure afforded by a sunny day is of com¬ 
mon experience, the value of sunshine.as an element in the 
climate, whether from the standpoint of health or spirits or 
of agriculture, is not often given the importance it deserves. 
Until recently no attempt has been made to record the 
amount or intensity, even in those places specially interested 
in agricultural meteorology. 
A certain amount of sunlight is recognized as a neces¬ 
sity for plant growth, for without it the development will be 
absent or unhealthy. With an increase in sunlight there is 
almost always an improvement in quality, and in the amount 
of essential oils; or in special qualities, as in sweetness, 
and an increase in the color of fruits and flowers. There 
is a decrease in the prevalence of certain diseases with direct 
sunshine. It has been known from time immemorial that 
dirt and darkness were conditions favorable for disease, 
while cleanliness and light were unfavorable. Molds and 
fungi, and the invisible but perhaps more important bac¬ 
teria, do not thrive in sunshine. Even in diffused light few 
bacteria develop, and direct sunshine is destructive to most, 
if not to all, injurious forms within a short time. Sunshine 
and the drying action of the air are unfavorable to such 
forms of life, and are Nature’s chief disinfectants. 
A sunny climate or a sunny home is thus more apt to 
give the conditions for such physical health as are necessary 
to permit of sunny dispositions. 
The charts show the amount of sunshine at P'ort Col¬ 
lins for 1900, as recorded by an automatic photographic re¬ 
corder and then transferred to the diagram. 
Aline is given to each day. The black line shows the 
duration of the sunshine and the hours at which it shone. 
When broken or absent, clouds are indicated. The longer 
the break, the longer the duration of the cloudiness. The 
diagram therefore shows the exact hours at which the sun 
shone during the year. It is noticeable that the forenoon 
had more sunshine than the afternoon, and that the winter 
months had comparatively little cloudiness. The relative 
amounts vary in different seasons, as a comparison with the 
charts in Press Bulletin No. 2 of 1900 will show. 
