with the symmetry of the curve, is nevertheless extremely interesting from the point of view of these investigations. It is evident that the influence of latitude has two components, namely, length of day and degree of temperature. The curve for Blacksburg indicates that, of these two components, the one representing the degree of temperature is by far the more important. There seems to be but little relation shown in these investigations between the hours of sunshine and the sugar content. In this respect the data for the present year are entirely in harmony with those of previous years.

In chart No. 2 are found graphically represented the percentage of sugar in the beet, the coefficient of purity in the juice, the temperature, and the average length of day. In this chart we find that two sets of the graphically illustrated data coincide in general in their magnitude and direction with the content of sugar, namely, the purity of the juice and the average length of day. In regard to the latter point there is again a noted variation in the case of Blacksburg, which has the shortest day of all the stations under observation. This fact is again illustrative and interesting, since it shows that it is not alone the hours of sunshine, or rather the hours of daylight, which form the dominant factor in the production of sugar. There is no doubt at all that there is a tendency to diminish the content of sugar by diminishing the hours of daylight. The greatest difference in the length of day between Blacksburg with the shortest day, and Madison and Geneva with the longest day, is 30 minutes. Yet the richness in sugar of the beet at Blacksburg was greater than that at either of the two stations mentioned. This illustrates the fact that of the two components in the factor of the long day-namely, duration of the light and temperature the latter is the more important. The temperature curve illustrates that the percentage of sugar is in inverse ratio to the elevation of the temperature; that is, in general, the higher the temperature the lower the content of sugar, and vice versa. For the present year this curve is not at all regular. There is an especial variation from it in the case of Lafayette, but if we take the two extreme points of Lexington and Agricultural College and connect them with a straight line, the general tendency of the factor above mentioned will be illustrated. The line which represents the sugar content of the beets of the various stations and the line which represents the average temperature at the same stations tend to form a figure like that of the letter X when platted graphically.

In chart No. 3 are platted the percentage of sugar in the beet, the total amount and monthly distribution of rainfall, and the altitude of the station. In this chart there is evidently but little relation between. the lines representing the factors of environment and the sugar content. The Blacksburg Station again introduces a great irregularity, since its altitude is so much greater than that of any other station.

CHART NO.3-SHOWING

PERCENTAGE OF SUGAR IN THE BEET,
ALTITUDE OF STATION AND RAINFALL RECORD.
EXPLANATION

PERCENTAGE OF SUGAR IN THE BEET

TOTAL INCHES OF RAINFALL DURING PERIOD COVERED.
INCHES OF RAINFALL DURING EACH MONTH
ALTITUDE OF STATION== =

DISTRIBUTION OF

RAINFALL BY MONTHS.

FT. ALTITUDE OF STATION.

ITHACA, N.Y.

THE BELT

FIG. 3.-Sugar content of the beet as influenced by the amount and distribution of the rainfall and

the altitude of the station, 1904.

LAFAYETTE,

IND.

ALTITUDE

JOIN-800 8...

6.6

4.6

700|כ

2000

The one really valuable lesson conveyed by this chart lies in showing that a high altitude may offset a low latitude in its relation to the content of sugar; this is shown in a remarkable manner in the case of the Blacksburg Station. It is perfectly evident from the data which have been collected and arranged that if the Blacksburg Station could be reduced to practically sea level, the character of the beets produced would be lower than that of the beets at Washington and Lexington, thus well illustrating the fact that the most depressing effects on the sugar content are produced by the combination of low latitude and low altitude. This is proved by the data obtained at Washington. The most satisfactory influences for the production of a beet rich in sugar are secured by the combination of a high latitude and a high altitude. There is an apparent exception to this in the case of the stations at Ithaca and Geneva. Ithaca is considerably higher than Geneva and only 26′ farther south, resulting in a lower temperature, and yet the beets grown at Ithaca have been uniformly inferior to those produced at Geneva. This relation is further discussed under the summary of the five years' work.

SUMMARY OF FIVE-YEAR EXPERIMENT.

Having discussed in previous reports" and in the foregoing pages of the present report the individual data collected at the different cooperating stations during the years 1900 to 1904, inclusive, it remains to bring these individual data together for comparison, in order to determine the average potency of each of the factors in the environment, and to this end the average figures for the five years are collected in tabular form and also expressed graphically, as has been done for each individual year. In the tables following are given the annual averages of agricultural, analytical, and meteorological data for the five years, and also in the general tables these averages for the five years as a whole, and the geodetic data as well: DETAILED ANNUAL SUMMARIES OF DATA, 1900-1904. Agricultural and analytical data for stations where irrigation was not used.

Agricultural and analytical data for stations where irrigation was practiced.

Meteorological data for stations where irrigation was not used.