460 Intelligence and Miscellaneous Articles. 



Vg l -^ n l —F L _t g^g -) 

 Slope, light load, T=-^ t -t 2 48EI 5 | 



qi •■■!. i , r ^^ 3 l 



Slope, heavy load, — 2 48EI* J 



Moment, light load, 



0>=0> — P# + m= — j^H 24 — 2~ + — 2~ 



Moment, heavy load, 



*' *FT i ^q + 'V w * + w H ce I ' ^ + ^ *» 

 *=-J EI +— 24""' 2 ^ + 2 •*" J 



Central moment, light load, $1 oc=-\= — tEIH — l ° l 2 ; 



Central moment, heavy load, $7 #=- j=— -EI ^— - — *Z 2 . 



Central deflection, light load, 

 y=T.r-P 2 +* » + F(with »- 5 )-b t^gf . V . 

 Central deflection, heavy load, 



h. (12) 



..(13) 



(14) 



.= -T'a?-Fgr + * o » + F^witha?=-0=^+ 



*Z t^o + 3^! /4 



384EI 



.l\ 



LVIII. Intelligence and Miscellaneous At tides. 

 leclanche's manganese elements, by j. muller. 



LECLANCHE'S voltaic elements have recently been extensively 

 recommended, although no statements as to their constants 

 have been published. I have thus been led to make a few experiments 

 with them. 



The arrangement of the elements is as follows : — A plate, or rather 

 a rod of gas-coke is placed in a porous clay cylinder, and the rest of 

 the space filled with a mixture of equal volumes of manganese (pyro- 

 lusite, Braunite) and of gas-coke in pieces the size of a pea. The clay 

 cylinder thus prepared is placed in a wide glass vessel filled with 

 solution of sal-ammoniac, in which is placed an amalgamated zinc rod. 



To determine the constants of this combination I used Ohm's 

 method. Three of Leclanche's cells, connected so as to form one 

 pair of plates, produced a deflection of 13° on a tangent- compass 

 the reduction-factor of which was 74 when this was connected with 

 the rheometer by only short thick copper wires. This deflection was 

 diminished to 5 0, 1 by the insertion of a Siemens's unit. Hence for 

 the electromotive force of a Leclanche's element we get the value 



e=10-76, 

 and for the essential resistance of one cell 



r=l-89, 

 if, according to Waltenhofen's proposal, we assume as unit that cur- 

 rent which furnishes one cubic centimetre of explosive gas in a 

 minute, and as unit of resistance a Siemens's unit (the resistance of 



