198 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Improved methods for the preparation of jams and jellies have 

 been devised and manufacturers have been assisted in improving 

 their methods and utilizing their waste products. In connection 

 with the States Relations Service, from time to time lectures and 

 demonstrations have been given at meetings of State agents upon 

 the methods of preparing jams, jellies, and preserves in the house- 

 hold. 



Miscellaneous. — A method has been developed, though not yet 

 applied on a large scale, by which a pure cane sirup can be made 

 which will not crystallize nor ferment. The studies upon the effect 

 of the different manufacturing processes upon the composition of 

 maple sirup and of sorghum sirup have been continued. A paper 

 has been published upon the composition of tamarind sirup. 



Beans produced in certain localities are not as highly esteemed as 

 their otherwise excellent quality warrants, because when soaked 

 they do not swell uniformly. It was found that a cuticular substance 

 is especially abundant in the epidermis of the hilum of those beans 

 which, when soaked, swell slowly The oxalic acid content of a large 

 variety of beans has been investigated. 



An investigation of the sauerkraut industry has shown that while 

 factory construction and management have largely followed German 

 models, the climatic differences between this country and Germany 

 have not been considered. Adequate temperature controls to dimin- 

 ish losses in waste liquor, kraut, and brine have not been provided. 



TECHNOLOGICAL INVESTIGATIONS. 



Dust explosions. — For the prevention of explosions in the thresh- 

 ing of grain an automatic fire extinguisher, a blower device, and a plan 

 of wiring the machines have been devised in cooperation with the 

 Office of Public Roads and the Bureau of Mines. They were described 

 in a joint bulletin with the Office of Public Roads, Bulletin No. 379, 

 and blue prints were furnished to all manufacturers of threshing ma- 

 chines in the United States by that office. Detailed information has 

 also been sent to underwriters and to farmers' mutual insurance 

 companies dealing in threshing-machine insurance. Plans were 

 made jointly with the Office of Public Roads to demonstrate these 

 devices in the field, with the assistance of the State experiment 

 stations of Idaho, Oregon, and Washington. The States of New 

 York and Pennsylvania have been assisted in the drafting of regu- 

 lations designed to reduce the danger from dust explosions and fire 

 in mills and elevators. With the assistance of the Bureau of Stand- 

 ards laboratory apparatus was constructed for the mechanical sepa- 

 ration of dust into fractions of definite size and density. By means 

 of specially designed apparatus the force developed by the explosion 

 of various kinds of dust has been measured. Results of the investi- 

 gation upon the inflammability of carbonaceous dusts and upon the 

 inflammability of carbonaceous dusts in atmospheres of low oxygen 

 tension have been prepared for publication. In cooperation with the 

 State College of Pennsylvania, the study of explosions in attrition 

 mills has been begun. 



Paper. — A test has been found to determine the strength of paper 

 when wet, which is a most important consideration in preparing spe- 

 cifications for photographic blue and brown print, bag, and wrapping 



