ABSTRACTS 



Authors of scientific papers are requested to see that abstracts, preferably 

 prepared and signed by themselves, are forwarded promptly to the editors. 

 Each of the scientific bureaus in Washington has a representative authorized to 

 forward such material to this Journal and abstracts of official publications 

 should be transmitted through the representative of the bureau in which they 

 originate. The abstracts should conform in length and general style to those 

 appearing in this issue. 



ELECTRICITY. — Radio instruments and measurements. Bur. Stand. 

 Circ. 74. Pp. 330. 1918. 

 The Bureau of Standards has issued a treatise on radio measure- 

 ments, for use by Government officers, radio engineers, and others con- 

 cerned. The circular inckides a development of the essential theory of 

 high-frequency measurements from simple but precise low-frequency 

 theory, the use of reactance curves in the rapid solution of problems, 

 descriptions of radio instruments, and formulas and data for radio 

 work. The full treatment of fundamental principles will make this 

 circular serve as a foundation for later publications which may be is- 

 sued by the Bureau on the general subject of radio communication. 



J. H. D. 



TECHNOLOGY. — Stahilized-'platform weighing scale of novel design. 

 F. J. ScHLiNK. Bur. Stand. Tech. Paper No. 106. Pp. 28. 1918. 



In this new scale the usual stabilizing element consisting of a pin- 

 and-link connection is replaced by a flexible elastic tape, band, or 

 wire. This design eliminates practically all the friction inherent in 

 existing stabilizing mechanisms. In stabilized-platform scales made 

 after the new design, friction is reduced to a very small amount, and is 

 unaffected by the position of the load. 



In the paper the earlier types of stabilizing elements are illustrated 

 and the limitations of each set forth. The theoretical considerations 

 underlying the conditions of equilibrium in weighing scales of the sta- 

 bilized-platform type are defined and the methods used in carrying out 

 the adjustment of such a scale are outlined. A discussion of the ef- 

 fects of static friction on the indications of scales is included and the 

 effect of the elimination of this friction in enhancing the accuracy of 

 weighings is shown. The paper includes nearly a score of illustrations 

 of weighing scales and scale details. F. J. S. 



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