60 Scientific Intelligence. 



to the wave length, provided the antenna resistances remain con- 

 stant. These experiments were carried on with flat-top antenna 

 heights of from 30 to 80 feet and wave lengths from approxi- 

 mately 1500 to 4000 meters. 



" (c) Taking account of the influence of antenna height and 

 wave length, the above equation may be extended and a general 

 day transmission formula written as follows : 



0-0015 d 



where the currents are given in amperes and all lengths in kilo- 

 meters. This formula has been tested for sending currents from 

 7 to 30 amperes, antenna heights 37 to 130 feet, wave lengths 

 from 300 to 3750 meters, and distances up to 1000 nautical miles. 



" In regard to the value of the day absorption it is only possi- 

 ble to say that the above expression is satisfied within the limits 

 of error of the observations. It is quite possible that when 

 observations are made at distances of 2000 to 3000 miles, the 

 value of the absorption coefficient will have to be corrected by 

 10 or even 20 per cent, as this amount of error could exist with- 

 out discovery at the distances covered in these experiments. It 

 is also possible that the square-root law relating the absorption 

 with the wave length is only an approximation." 



The other papers in the same number include one by C. E. 

 Waters on the behavior of high-boiling mineral oils on heating in 

 the air ; another by J. R. Cain on determination of vanadium in 

 vanadium and chrome-vanadium steels; by E. Buckingham and 

 J. H. Dellinger on the constant C 2 of Planck's equation for the 

 intensity of radiation ; by T. T. Fitch and C. J. Huber on Ameri- 

 can voltmeters and ammeters ; by P. G. Agnew on the current 

 transformer ; and by H. S. Carhart on thermodynamics of con- 

 centration cells. 



Circular No. 24 (pp. 41) gives a summary of the published 

 work of the Bureau of Standards, which is remarkable in extent, 

 considering the short time since the Bureau was established. 

 Seven volumes of the Bulletin have appeared, the first in 1904-5 ; 

 in all 174 papers are enumerated, some of these now in press ; 

 these are here classified and their contents briefly indicated. A 

 series of thirty-one circulars of the Bureau is also enumerated ; 

 these give the regulations under which the tests and comparisons 

 of the Bureau are made, with a general statement as to its work. 



8. Annual Tables of Constants and Numerical Data, Chemi- 

 cal, Physical and Technological. — The first volume of the Annual 

 Tables of Constants and Numerical Data, Chemical, Physical 

 and Technological, compiled and published by an international 

 commission, appointed by the 7th International Congress of 

 Applied Chemistry (see Science, August 4, 1911, p. 158), is now 

 open to subscription. Subscription blanks, the terms of sub- 

 scription and descriptive leaflets may be obtained from any one 



