Viewing page 33 of 195
This transcription has been completed. Contact us with corrections.
60 Monday Oct 9 [[entire paragraph notated as error, as per left column notation]] after several attemps to descover the cause of the anomaly which was exhibited in the last experiment, I found it due to charging of the pane of glass which I interposed between the two balls to prevent the transfer. When this was removed, and the balls seperated to the distance of two inches, the needle in the spiral [[underline]] b [[/underline]]] indicated a current in an upward direction, or in accordance with my previous hypothesis, and also my previous experiments. The effect of the glass was to produce such an arrangement as was given in the experiment above, the last on the last page. The one side of the glass was charged + and the other was (the one next the receiving ball of the induced current) was negative per the result. In all the subsequent experiments, the use of glass must be resorted to with a knowledge of the effect. I was mistaken in the last result, the glass being removed, the needle still indicates a current down tows the ground, and no arrangement I have yet been able to make will produce a contrary result. Exp. 4 [[Diagram shows a circle with perpendicular line on top with positive with line and loop underneath showing a variable resistor]] When the jar was removed and and an insulated plate led over the ball, the current was upward at the moment a spark was drawn from the dist. end of the machine. The effect cannot therefore be due to the redundant or free electricity, for this would tend to produce a different result. [[Initialled NB in right margin]] The fact that a current is sent off in every direction from a wire transmitting a discharge, will explain the induction produced in thunder storms. See a case in Comptes Rendus for 1843 Aug 4th Cathedral of Strasbourgh. [[end page]] Monday Oct. 9 61 [[Diagram of plane with two wires at perpendicular angles to plane at either end. Wire running through two balls at top of each perpendicular wires, wire joints, protruding from plane marked at one end a and the other end b. + sign over perpendicular wire on right with directional arrows pointing to the left. A fuse with wire and resistor just after wire joint b]] [[note in left margin]] Exp. 1 [[/end of note in left margin]] Arranged the apparatus as in the figure-placed the receiving ball near the plus end, made the discharge. The needle indicated a current from the wire. The receiving ball was then moved toward the negative end, the result was the same, the needle still indicated a current towards the earth or from the wire. The induction therefore through the whole wire appears to be due to an accumulation of the fluid in the wire, and not to its being in a polar state the one end being +, and the other minus, and this is in accordance with the puzzling results I have obtained in the experiment of this morning. [[note in left margin]] Exp. 2 [[/end of note in left margin]] Next attached a ball to the end of the wire [[underline]] a [[/underline]]while the other end was placed in connection with the conductor of the machine. When a spark was drawn from the ball, a current was produced in the discharging wire [[underline]]from [[/underline]] the earth contrary to the direction of the current I have before obtained. [[note in left margin]] Exp. 3 [[/end of note in left margin]] Next connected the ball [[underline]] a [[/underline]] with the earth and then threw sparks on [[underline]] b [[/underline]]. The needle was now magnetized as if a shock had passed through the wire, or in such a manner as to indicate a current from the wire to the earth. Experiment 2 was varied by connecting the end b. with the machine, and then drawing sparks from the same end, the needle was magnetized by an ascending current. The results obtained in Experiment 3, page 59, are in accordance with the facts here obtained. The jar is charged, and the electricity as it passes out of the ball, sends a current in the direction towards
