138 Intelligence and Miscellaneous Articles. 



netic force in a direction contrary to that followed by wires of 

 other materials, which it does not do. 



In view of these difficulties, it seems hardly possible at present 

 to accept Prof. Boltzman's method of calculating the velocity of 

 electricity. 



Any one desiring to see Prof. Boltzman's note wiL find a trans- 

 lation of the same in the Philosophical Magazine of April 1880, 

 p. 307. A rather confusing inaccuracy in translation is, however, 

 to be found about the middle of page 308, in the sentence, "Hence, 

 if the force above denoted by h itself acts upon &c. This should 

 read, " Hence, if the force above denoted by h acts upon the mo- 

 vable electricity itself in the gold-leaf &c." The position of the 

 pronoun is here a matter of considerable importance, as any one 

 will see who reads Prof. Boltzman's note with care. — SHliman's 

 American Journal, July 1880. 



ON A NEW FORM OF GALVANOMETER. BY L. GOSTYNSKI. 



I have the honour to introduce to the Academy a new galvano- 

 meter for thermoelectric currents, which is distinguished particu- 

 larly, from all those with which we are familiar, by the combination 

 of two astatic systems having the same direction. The chief ad- 

 vantage of this apparatus consists in the proportionality, which I 

 have been able to extend up to nearly 90° ; this renders unneces- 

 sary the construction of Tables, which, besides, are often inad- 

 equate. 



Having to make and to verify a great number of determinations 

 respecting the transmission of heat through various thicknesses of 

 water, I sought for means of measurement at the same time simple, 

 convenient, and precise. The apparatus in question combines these 

 conditions, and can be rendered highly sensitive. It has a conti- 

 nuous induction-coil — that is, without a slit for the passage of the 

 astatic system. A U-shaped aluminium wire, suspended by a 

 cocoon-thread, supports two astatic systems, both having the same 

 direction, crossing at an angle of about 45°, and joined one to the 

 other. In a small vertical mirror surmounting the U-wire, and 

 carried along by the double astatic system in its motion of rotation 

 under the action of the current, the divisions of a semicylindrical 

 scale having the cocoon-thread for its axis are reflected, and project 

 themselves upon a small vertical fixed sight placed behind the 

 mirror. The zero of the scale corresponds to that position of the 

 TJ-wire for which one of the astatic systems is parallel to the turns 

 of the coil, the direction of the current being such that the other 

 system moves towards the startiDg-point of the first. 



For nearly two months I have been verifying the proportionality 

 of various deflections to the left and to the right of zero ; and that 

 proportionality has been confirmed by more than fifty series of cross 

 observations, each series comprising at least six partial determina- 

 tions, 



