938 



SCIENCE. 



[ N. S. Vol. XVII. No. 441. 



1 



solutions, which table has been prepared by 

 the Imperial NormaleichungsJcommission. At- 

 tention has also been paid to the determina- 

 tion of the alkalinity of first products, to the 

 determination of sucrose in the presence of 

 invert-sugar, raffinose, etc. 



About one half of the book is given over to 

 sugar-analysis, or rather, to be more precise, 

 to the analysis of sugar and sugar-containing 

 ■compounds. The rest of the work treats of 

 the analysis of bone-black, water, limestone, 

 gas-analysis, fuels, fertilizers and so on, and 

 in most of these sections considerable changes 

 and improvements are also to be noted. 



A recalculation of all numerical data and 

 problems was made imperative by adoption 

 of 16 as the atomic weight of oxygen. 



Paper and print are excellent, and the 

 numerous illustrations a feature of value. 



F. G. WiECHMANN. 



SOCIETIES AlSfD ACADEMIES. 

 THE AMERICAN PHYSICAL SOCIETY. 



The spring meeting of the Physical So- 

 ciety was held at Columbia University, New 

 York City, on Saturday, April 25. An un- 

 usually large program of fifteen papers was 

 presented, and the attendance was above the 

 average. 



The first article was by IT. T. Barnes and 

 E. G. Coker, and dealt with the ' Plow of 

 Water through Pipes in Stream Line Motion 

 with Special Reference to the Critical Ve- 

 locity.' By taking every precaution to have 

 absolutely quiet water in the tank which 

 supijlied the pipe studied, it was found pos- 

 sible to increase the critical velocity much 

 beyond the limit found by previous observers. 

 The presence of little disturbances in the 

 water entering the pipe seems to have a 

 strong tendency to break up stream line flow 

 into an irregular eddy flow. For small pipes 

 the authors found that two critical velocities 

 might be observed. As the velocity was in- 

 creased from a low value a speed was reached 

 at which stream line flow ceased and eddies 

 formed. If the velocity was increased still 

 more, another critical stage was reached, be- 

 yond which the flow again occurred in stream 

 lines. 



Messrs. H. T. Barnes and D. Mcintosh de- 

 scribed a form of platinum thermometer 

 especially designed for work with the con- 

 tinuous flow calorimeter and avoiding many 

 of the difficulties met with in previous forms. 



In a paper on ' Architectural Acoustics ' 

 G. W. Stewart described a series of experi- 

 ments made in the auditorium of Sibley Col- 

 lege at Cornell University. The reverbera- 

 tion in this hall when first completed was so 

 bad that a speaker could hardly be understood 

 at all. It seemed to offer a good opportunity 

 to test the methods and conclusions developed 

 by Sabine in his work on architectural 

 acoustics. Mr. Stewart found a complete 

 agreement between the results obtained by 

 experiment and those computed upon the basis 

 of Sabine's theory. 



A paper on the ' Spectral Energy Curve of 

 a Black Body at Room Temperatures' was also 

 presented by Mr. Stewart. In order to obtain 

 radiation from a body at room temperature the 

 vane of a radiometer was used as a radiating 

 surface, while in front of the slit of the mir- 

 ror spectrometer used was placed a body at 

 the temperature of liquid air. Under these 

 circumstances, since the radiation from so 

 cold a body is practically nil, the cooling of the 

 radiometer would be due to its own radiation, 

 and the deflections observed in the different 

 parts of the spectrum would measure the radia- 

 tion for particular wave-lengths. The curve 

 showing the distribution of energy in the 

 spectrum had the same general form as that 

 observed at higher temperatures. The maxi- 

 mum occurred at 9.2 /i, the position of the 

 maximum differing from that computed by 

 Wien's formula by about 0.6 /j.. The energy 

 curve was compared with that computed from 

 Planck's theory, and variations of ten per 

 cent, were noticed, although the curves were 

 alike in general form. In view of the fact 

 that the maximum deflection obtained was 

 not quite 4 mm., such differences were not 

 surprising. 



The results of determinations of the specific 

 heats of certain organic solids were presented 

 by W. F. Magie. Fourteen substances were 

 examined, the Pfaundler calorimeter being 

 employed. The results were compared with 



