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80 Friday Oct 20th 1843 [[line wavy]] The secondary current may be represented by a wave in reference to its axis thus: [[image of drawing]] the beginning induction of the discharge of the jar will give an intense current which will be of very short duration. the end ^[[insert]] ing [[insert]] of the jar current will give a wave in the + direction, but since the ending takes place more gradually the than the beging, the wave will not be so intense. Again the rebound of the jar current will produce anothe wave adverse to itself, and hence in the + direction, and the stoppage of this another in the same direction with itself, and hence adverse to the primary wave, and there minus, this is represented by [[underlined]] a [[/underlined]], the others by [[underlined]] c [[/underlined]] [[underlined]] b [[/underlined]] and [[underlined]] e [[/underlined]]. The next rebound will produce an other which will again be on the same side with the first induced current and so on. The fact that more than one hole is piered in card, is mentioned by Mr Etrick, Annules of Electity,vol 2, x 3g. [[end page]] [[start page]] Monday 23rd 1843 [[squiggly line]] Exper. on the holes pierced in cards by the secondary current 81 Commenced this morning the Repetition of Matteucci's experiments, to determine the direction of the induced current by means of the pierced card. + - The points were placed 1/4 of an inch apart, with one jar, charge 60 [[strikeout]] three [[/strikeout]] two small holes near the - minus point, current adverse. + - charge 80, [[underlined]] three [[/underlined]] holes nearer the minus pole. The larger hole was ragged; one jar, distance same + - charge 90. Distance same, [[underlined]] three [[/underlined]] holes nearer the minus side. When these holes are examined with a magnifying glass, the larger appears ragged and triangular. + - All things remaining about the same with the same charge, a large irregular hole was formed nearer the - minus end. + - Small charge elect 30 [[degree symbol]], hole near the minus side. + - Distance 1/2 an inch, single hole near the [[underlined]] minus [[/underlined]] pole. At this distance, a brilliant spark appeared between the points of the needle. __ When the points were removed to a greater distance, so that the spark could not pass, a singular hollow sound was produced as if the discharge from the battery met with an interruption. + + Distance rather more than 1/2 an inch. One hole of a ragged appearance near the minus pole. NB all the larger holes appear double and sometimes triangular.
