Febetjaey 17, 1911] 



SCIENCE 



257 



saw them clearly with " phosphornebel " is pre- 

 sumably due to the fact that, the kinetic energy 

 of agitation of all particles being the same, the 

 velocity of agitation of a platinum particle would 

 be but about one fifth of that of a particle of like 

 size in a cloud of phosphorus despite the fact 

 that, as shown by Einstein's formula, 



the displacement along J in a time t would be 

 the same for the two particles. In other words, 

 while the " drift " of a Brownian particle is in- 

 versely proportional to its radius and independent 

 of its mass, the " instantaneous speed " of a par- 

 ticle of given radius is inversely proportional to 

 the square root of its mass. There is then noth- 

 ing whatever in Ehrenhaft's work to raise a 

 suspicion as to the correctness of any of the 

 conclusions which have been drawn from our 

 observations. 

 The International Electrical Units: Dr. E. B. 



Rosa. 



The international electrical units current in all 

 countries throughout the world are based upon 

 the definitions and numerical values adopted ar 

 Chicago in the International Electrical Congress 

 of 1893, except that the numerical value of the 

 standard cell, adopted by Germany and some 

 other countries, was slightly different from that 

 recommended by the congress, which latter value 

 was legally adopted in America, England, France 

 and some other countries. In order to secure in- 

 ternational uniformity so that the ampere and 

 the volt, as well as the ohm, should be the same 

 in every country, an international research was 

 carried on at the Bureau of Standards, during 

 April and May of last year, in which the stand- 

 ards of the national laboratories of England, 

 France and America were compared and the silver 

 voltameter was investigated. As a result of this 

 cooperative eflTort, the International Committee 

 on Electrical Units and Standards has agreed to 

 recommend to all the governments represented in 

 that committee the adoption of a new value for 

 the Weston Normal cell, which has the effect of 

 changing the numerical value of the international 

 volt and also of the international ampere. The 

 new value of the Weston Normal cell, at 20° C, 

 is 1.0183. The previous value in America was 

 1.0191, whereas in Germany it was 1.0186, and 

 in England for the last two years it has been 

 1.0184 although previously it was higher than the 

 value in this country. There will be, as soon as 

 the new value has been generally adopted, inter- 



national uniformity with respect to the value of 

 the units of resistance, current, voltage and 

 power. It will, of course, require some time 

 before the new values come into general use, 

 although it is expected that they will be oiScially 

 adopted in all countries at an early date. The 

 Bureau of Standards adopted the new value Jan- 

 uary 1, 1911, and certificates issued by the 

 bureau after that date will be in terms of the 

 new units. The difference is, of course, inappre- 

 ciable in ordinary engineering operations, but is 

 very important in precise measurements, and is 

 appreciable even in photometric measurements of 

 electric lamps, in which the voltage or current, or 

 both, are given. 

 Osborne-Reynolds's Theory of Gravitation: Mr. 



John Mackenzie, M.E., Minneapolis. 



In contrast with the ordinary view that space 

 is filled with an ether of very low density, 

 Reynolds's view is that space is filled with a 

 granular medium of very high density. The 

 grains are small, hard spheres. The density of 

 this medium is 10,000 times that of water. The 

 grains are usually arranged in " normal piling." 

 Where matter exists this arrangement is dis- 

 turbed and a less number of grains occupies the 

 same space. This is " abnormal piling." Matter 

 is then negative mass. An atom of matter con- 

 sists of a nucleus of grains in normal piling sur- 

 rounded by a shell of grains in " abnormal piling." 



The grains have motion relatively to one an- 

 other, but the mean path of the motion is only a 

 very small fraction of their diameter. This mo- 

 tion renders the medium elastic. An experiment 

 with billiard balls was used to illustrate mass 

 motion in space, defined as a " coming in of 

 grains in front and leaving of grains in the rear." 



To illustrate the difference between normal and 

 abnormal piling of grains a rubber balloon filled 

 with sand and water was subjected to pressure 

 by placing a 75-pound weight upon it. The sink- 

 ing of the liquid in an attached manometer tube 

 showed that the addition of the weight increased 

 the total volume of the intergranular spaces occu- 

 pied by the water. 



Reynolds holds that there is no attraction 

 residing in masses of matter, but where abnormal 

 piling (bodies of matter) exist, the pressure of 

 the surrounding medium tends to restore normal 

 piling and incidentally masses are driven to- 

 gether. This is gravitation. 



The theory is also applied to the explanation 

 of cohesion, electricity, magnetism, light and 

 other physical phenomena. 



