18 Trans. Acad. Sci. of St. Louis. 



ered, and previous results have been confirmed. The dif- 

 ferences between th two sides of the angle are, however, 

 less marked than those obtained when the plate was en- 

 closed. It is, however, felt that additional attention must 

 be given to this branch of the subject. There does not 

 seem to be any reasonable doubt of the existence of mo- 

 mentum effects at the angle, but the action is complicated 

 bv other effects, some of which have not received sum- 



v 7 



cient attention to permit of discussion at present. 



For example, the effect of spark discharges of this 

 character on a platinum wire of 0.005 cm. diameter may 

 be cited. After such a wire had been in daily use for 

 about three weeks as an angle-wire, it was found that a 

 system of regular wavelets had formed over its whole 

 length, of about 80 cm. The waves were very regular in 

 form. The wave length was 0.090 cm. and the amplitude 

 from crest to crest was 0.015 cm. The wire was under 

 tension of 4 grams weight. The wet cloth resistances 

 were in constant use, so that electrical oscillations were 

 eliminated. These wavelets seem to be much more reg- 

 ular in form than those described by Plante. This may be 

 due to a difference in the conditions of the discharge. He 

 is said to have used a continuous current from storage 

 cells. 



That the linear velocity of the current particles in a 

 conductor must be very great follows from the following 

 considerations, which were pointed out by the author in 

 1895 : 7 



Imagine two conducting spheres having radii equal to 

 that of the earth, or 6.37 XlO 8 cm. Let them be charged 

 to potentials +25 and — 25 volts. Connect them with a 

 wire containing in circuit a 50-volt 1-ampere lamp, the 

 resistance of the wire conductor being neglected. In order 

 to maintain the potential difference on the two spheres 

 constant, and thus maintain normal candle power in the 

 lamp while all of this store of electricity is being used, 



7 Nipher. Electricity and Magnetism, p. 390, § 222. 



