﻿Intelligence and Miscellaneous Articles. 237 



selves to the limiting case in which the conductors are in metallic 

 contact (which in some cases might possibty be applied instead of 

 voltaic electricity), the quantities of electricity produced are easily 

 obtained in absolute measure if the magnetic actions of the current 

 they form are observed. The reduction of the measurements of the 

 intensity of the current to mechanical units, which my father and 

 Weber executed, renders it easy to express quantities of electricity 

 in electrostatic units. 



The machine investigated was constructed by Schultz of Berlin, 

 according to the pattern described by H. Holtz in vol. xxx. of this 

 Magazine. The fixed disk has two coatings ; the moveable one has 

 a diameter of 400 millims. Where it is not otherwise expressly 

 mentioned, only two of the four combs which were opposite the coat- 

 ings were at work. 



By velocity of rotation is understood the number of turns of the 

 handle in a second, one of which corresponds to six turns of the 

 glass disk. 



The two conductors were connected (a moist thread being inter- 

 posed) with the ends of the wire of the same multiplier as was ar- 

 ranged for the research of Weber and my father, and which is de- 

 scribed in the fifth volume of the Proceedings of the Royal Academy 

 of Saxony, pp. 259 & 289. The 5635 turns of its wire, amounting 

 to about three miles, were completely protected against the forma- 

 tion of short circuit by careful insulation. 



The intensity of the current which flows through the coils of this 

 multiplier and deflects the needle through cp, is in absolute magnetic 

 measure 



T 

 262-1 ° r 



nr, with the present value of the horizontal intensity of terrestrial 

 magnetism for Gottingen T=T844, 



8=0-00704 log <j>. 



In what follows, the distance of the scale from the mirror of the 

 magnet was = .1400 divisious ; hence, if p represents the deflection of 

 the needle in parts of the scale, for small values of p we can put 



. 0-00704 nnnn „ nnn 

 ?= ^800-^ = '° 0000251 ^ 



The very powerful damper completely stopped the needle after a few 

 minutes ; and with a little practice it was possible so to regulate the 

 velocity of rotation by a seconds' watch, that the deviations only 

 amounted to a few divisions. 



It was surprising to find the working of the machine as good as 

 constant on different days. Although the absolute moisture of the 

 air in the room of observation was between 9 and 14 grms. of water 

 in a cubic metre, and the relative varied between 0-42 and 0-58, 

 and the greatest length of spark was subject to great variations, as is 

 usual with these machines, yet the inequalities observed in the in- 



