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196
Febry 11th 1845
[[image]]
1 - Made an arrangement for getting the electrical figures with the large conductor, and the wire going to the wall. Frst, the glass was without coating on the under side, and in this case, the figure was formed around the plus pole alone.

2 - Next the powder was sprinkled over the plate of glass coated on the lower side with tin foil, with this arrangement the figure was produced at each pole the same as in [[image]] the case of an electrical jar.

3 - Repeated the experiment with the uncoated glass with the same result, the figure was exhibited only at the plus pole.

4 - Tried the same experiment with the jar, and the uncoated plates formed the result the same as with the large conductor, the figure was not produced around the negative pole. This is not in accordance with the result of the first exp p 190. In this case however, a small jar was used, while in the other, one of the tall jars of the small battery was employed.
also in the above experiment, I found that the large conductor was connected with the machine.

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197
Febry 11th 1845

The rationally of the effect in exp No 2 last page, appears to be that the charge in [[advery?]] by induction renders the tin foil under the glass strongly negative under the minus pole, and the electricity [[strikethrough]] fo [[/strikethrough]] under the plus pole is driven out on all sides.

Repeated the experiment with the small jar and the plated and the unplated glass, I should say coated and uncoated, with the first, the spark passed over a distance of four inches, with the latter it would not pass over a distance of more than two inches, this clearly establishes the fact that the coating of a pane of glass on one side favours the passage of electricity over the other, induction of an opposite kind takes place, which must precede the charge and assist in its passage through the air.
^[[See observations on the passage over the surface of water 175p]]

Tried to produce the figures with three jars, but did not succeede very well. The jar reqiers to be manually charged to produce the effect well. When the conducting rod was brought in contact with the knob of the battery, the discharge did not pass at the first attempt, but a small quantity of the electricity was drawn from the inside, which instantly produced an effect at each pole on the plate, an effect evidently due to the reversal of the tension from the inside which drew the electricity from the negative pole.