[LB050360], Letter from Alfred Ord Tate to New York New Haven and Hartford Railroad, N E Smith, July 18th, 1891
https://edisondigital.rutgers.edu/document/LB050360
Transcription
July 18, 1891. W.B. Smith, Esq., C.T.D., N.Y., N.H. & H.R.R. Co., New Haven, Conn. Dear Sr:- Your letter of 4th instant, has remained unanswered owing to my absence. I believe the reason for the change produced by reversing the battery is attributable to the weakening of the field magnet poles in the meter, since the residual magnetism of the previous current would now be in opposition to the direct magnetism of the new current. This is the most reasonable explanation I can offer of the phenomenon. I think you asked me for the resistance of the german-silver shunt in a previous letter. The resistance of this shunt is one ehm. The resistance of the field is 1.84 ehms; and of the armature .225 with the brushes on one bar. Yours very truly, A.O. Tate