68 
METEOROLOGY OF 1 897. 
the full line extends from the sunrise to the sunset line. If 
a cloud obscures the sun for a time, this is indicated 
by a break in the line, and the duration of the obscuration is 
shown by the length of the break. Hence the broken lines rep- 
resent intermittent sunshine, or days of floating clouds. The 
spotted character of the diagram in the same months shows 
a feature noticeable in our mountain meteorology; fair 
weather in the forenoons, and of floating cumulus clouds or 
local thunder storms in the afternoons. 
§71. The chart has been made from the photographic 
record made by means of the Pickering sunshine recorder, 
already described. As the intensity of the sunlight is not 
enough to record near sunrise or sunset, some element of 
judgment is involved both in the table and in the diagram 
in estimating the period of about half an hour near those 
times. As the diagram and the measurement were made 
by different persons, there may be a slight discrepancy in 
estimating this period in the two cases. 
The distribution of the sunshine through the year is 
noteworthy, and to those interested in Colorado climate, 
whether as agriculturists or as health seekers, the chart 
will prove worthy of careful examination. 
It will be noticed that there are many days on which 
the sun shines throughout the whole day; there are very 
few when it does not shine for a greater or longer time, 
but there were several days in 1897 when no sunshine is 
recorded by the sunshine recorder. The groups of sun- 
shiny days are also noticeable in the diagram, their occur- 
rence usually being at the same time as a wave of high 
barometric pressure. 
§ 72. The important effect of sunshine on the matura- 
tion and quality of grains, the coloration of fruits and 
flowers, and its important influence from a sanitary stand- 
point, are too well recognized, to need more than a refer- 
ence here. From the standpoint of Agricultural Meteor- 
ology both the amount and the intensity of sunlight are 
among the most important of the elements to be observed 
and studied, and while the connection between the sunlight 
and the growth and development of plants is complicated 
and surrounded with many difficulties, some of the definite 
relations are not beyond the possibility of determination. 
Records of the amount of sunshine since 1888 have been 
kept by similar methods at a number of stations and later 
it is hoped to give a more complete discussion of the ques- 
tions relating to sunshine and its agricultural importance. 
