FE. H. Hall— Velocity of an Electric Current. 53 
direction equal to 3,000 x 200 =600,000 dynes, a force equal 
to the weight of about 600 grams, acting upon each unit . 
length of the gold leaf strip. Thus in following out Prof. 
Boltzman’s assumption to what seems to me its necessary con- 
Sequences we are led to a manifest absurdity. 
Another objection to the above assumption, and a serious 
one appercally, is found in a fact not known to Prof. Boltzman 
when his note was written. eo 
