October 18, 1901.] 



SCIENCE. 



587 



quoted above. If we compare the bunsen 

 and the single tip curves, we see that they 

 do not agree in all respects. The eleva- 

 tions due to the emission of the H^O gas 

 have not the same relative values in the 

 two cases, but this discrepancy disappears 

 when corrections are made for slit widths. 

 The band at 2.Sfj- does not appear in the 

 bunsen flame and this fact makes its pres- 

 ence in the other somewhat in doubt. 



The changes produced in the correction 

 of the curves possess several points of in- 

 terest. The maximum of intensity is 

 shifted considerably toward the violet, 

 appearing in the corrected curve at about 



Using Langley's method of finding the 

 ratio of the area in the visible portion of 

 the spectrum, to the area of the entire curve, 

 the radiant efl&ciency was calculated. The 

 value for the cylindrical flame is 0.100 and 

 for the flat flame 0.131. The latter value 

 is not verj'^ reliable, but there is not much 

 doubt but that the radiant efficiency of the 

 flat flame is the larger. Stewart and Hoxie, 

 using a modification of theMelloni method, 

 found the value 0.105 for the flat flame. 

 (To be printed in the Physical Review.') 



3. ' Experiments on a New Form of 

 Standard High Electrical Resistance ' : H. 

 C. Parker. (By title.) 



4. ' Variation of Contact Resistance with 

 Change of E. M. F. ' : H. C. Parker. 

 (By title.) 



5. * On Flutings in a Sound Wave and the 

 Forces due to a Flux of a Viscous Fluid 

 around Spheres': S. E. Cook, Washburn 

 College. 



The author shows that the forces due to 

 a perfect fluid are not sufficient to produce 

 the laminse and flutings in a sound wave, 

 but that there are other forces which are 

 probably due to the viscosity of the vibrat- 

 ing media. That there must be other forces 

 was first manifest by a series of experi- 

 ments with air, carbon dioxide, chlorine and 



hydrogen as media, using various materials 

 to foria the laminae, including filings of 

 coin silver and platinum. 



The author also shows that flutings are 

 not confined to a stationary sound wave but 

 are capable of being produced by direct 

 sound waves on an open surface. 



A mica disk, threaded on a fine wire in a 

 resonance tube, was caused to vibrate in uni- 

 son with the prong of a large tuning fork, 

 whose frequency was 32 per second. Koen- 

 ig's equations for the forces due to a perfect 

 fluid when reduced to their final form are : 



X-- 



z 



3l2TvpE^Ei^Wo3 



^TTpBm^^ fFo^ 



M=pB^^WQSvn'iO. 



P = density of medium, i?, B,^, R^ are the 

 radii of the sphere or disks, W^ the velocity 

 of the stream. This gives repulsion par- 

 allel and attraction perpendicular to the 

 stream lines. The forces were studied by 

 first allowing RR^ to vary while p and W^ 

 remained constant. Then p was varied 

 while all other factors were kept constant, 

 and it was shown that 



Xa Z^ if 2 ^ P2 



when jOj was the density of carbon dioxide 

 and p.^ that of air. 



A further study of the forces was made 

 with sealing-wax spheres and it was found 

 that when the spheres, whose radii were less 

 than 1 mm. were at a greater distance 

 than one-half their diameter apart, they 

 followed the perfect fluid forces, but when 

 they were less than one-half their diameter 

 they were repelled perpendicular, and at- 

 tracted parallel, to the line of flow. 



The author reaches the following con- 

 clusions : 



1. The conditions for the formation of 

 laminae are found whenever there is a flux 

 of a viscous fluid around solid particles. 



