96 DEPARTMENTAL KEPORTS. 



All these problems connected with the nature of road materials are 

 of a physical and chemical nature. It is true they can all be worked 

 out by actual experience, but experience in this case is extremely 

 costly. The most certain and economic way of solving these problems 

 is in the laborator3\ There small quantities of material can be sub- 

 jected to all the tests of stress, friction, and cementation to which 

 they would be subjected if actually placed in a road for use. Thus, 

 with only a very small quantity of material, had at a comparatively 

 low cost, the actual value of the material can be ascertained with a 

 high degree of accuracy. 



For the purpose of studying these problems, a laboratory, as has 

 been stated, was established in the basement of the chemical building, 

 in which a large X)art of the machinery necessary to the testing of road 

 materials has already been installed. No chemical work in connection 

 with the structure of road materials, in relation to their surfacing and 

 cementing properties, was undertaken during the year, by reason of a 

 lack of chemical force. Full j)reparation, however, was made for the 

 beginning of this interesting i^art of the investigations during the 

 present fiscal year. 



INVESTIGATION OF THE INFLUENCE OF ENVIRONMENT ON THE SUGAR 



CONTENT OF THE BEET. 



Since the beginning of the investigation of the chemical composition 

 of sugar-producing plants by the Division of Chemistry, now more 

 than a quarter of a century ago, the great influence of environment, 

 that is, soil and climatic conditions, upon the sugar content of the beet 

 has been recognized. By reason of the extreme variation in environ- 

 ment of this nature in different parts of the United States, it is evi- 

 dent that this influence is more pronounced in the case of the beets 

 grown in this country than in those grown in Europe. In a general way, 

 for the last fifteen years the Division had been able to point out with 

 a reasonable degree of accuracy the areas in the United States which, 

 in the light of the investigations which had been conducted, were best 

 suited to the growth of sugar beets with a maximum content of sugar. 

 These widely extended investigations, covering a period of nearly 

 thirty years, formed a substantial basis from whicli to begin in a more 

 systematic way the practical study of the influence of environment. 



The object in view was to determine, first of all, the exact force of 

 environment, and, second, by analysis of the various factors of environ- 

 ment to determine those which were most active either in increasing 

 or diminishing sugar content. 



It is evident that in a study of this kind the Division must have 

 recourse to the collaboration of otlier Bureaus and workers. In the 

 present instance the Division was most fortunate in securing the active 

 cooperation of the Weather Bureau in determining as nearly as pos- 

 sible tlie conditions of the weather during the jjeriods of growth of the 

 experimental fields. It was also fortunate in securing the active and 

 heart}^ cooperation of a number of the agricultural experiment stations, 

 which were selected with a view of securing as widely different co)i- 

 ditions of environment as could be obtained. The stations coopera- 

 ting in tliis work were those of Indiana, Iowa, Kentucky, Michigan, 

 North Carolina, Utah, Virginia, Wisconsin, and the two stations in 

 New York. The plan adopted for the work was as follows: 



A high-grade beet seed of uniform character was distributed to 

 each of the collaborating stations. Portions of the same lot of seed 



