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Wednesday Oct 25th 1843 Magnetism of Needles by the Primary Current
The motion of the galvanometer in these experiments was as if it were acted upon by more than one current
charged the battery to 30º current [[underlined]] Direct [[/underlined]]
Made various attempts this afternoon to get a reversal of the poles of a needle by the direct discharge but did not succeed.
First sent charge from Franklin battery through copper bell wire about 18 inches long. Needles placed at different altitudes above, from contact to one inch, all magnetized +. The needles were small No 9.
[[image- sketch wire wrapped wax block]] Next wrapped long piece of thin wire around a block of bees' wax, placed needle transversely, sent through charge from single jar, needle always magnetized +.
The needles in the case of a single jar, highly charged, were more highly magnetized than with the battery in the experiment with a straight wire.
Thursday
[[margin note]] Needles no 12 [[/margin note]] Repeated the last exp with the battery charged to 60°. The needles were all magnetized [[underlined]] plus[[/underlined]], except the one nearest the wires, which was about one tenth of an inch distance, this was magnetized scarcely at all.
Repeated same battery charge 45°
[[margin note]] Needles no 12 [[/margin note]]
Needles distance from wire Deflect
1 1/10 of an inch 0
2 .2 0
3 .3 -0
4 .4 +5°
5 .5 +15
6 .6 +19°
7 1.0 +17°
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Thursday Oct 26th 1843 Magnetization of Needles by the primary current 93
From the last experiment, it is evident that the feeble magnetism of the needles as given vol 2, p 271, 272, [[?]] is not due to position of the wire being confined to the middle of the needle, since in this case it is under the whole length, and yet the needle is not at all magnetized, or in the adverse direction.
[[margin note]] used in this exp [[/margin note]]
[[Box is drawn around the following table, with an asterisk to the right of the box]]
[[margin note]] needles no 12 [[/margin note]]
Repeated Battery charge 60°
Needles distance Deflect
1 .1 of an inch 0
2 .2 0
3 .3 0
4 .4 +2°
5 .5 +15°
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[[underlined]] NB [[/underlined]]
In these experiments, care was taken to place the needles at right angles to the magnetic meridian, so that no influence from the earth might affect the result.
[[margin note]] same coil around beeswax [[/margin note]]
Needles with temper drawn to bluness
Battery 60°
[[margin note]] Needles No 12 temper blue[[/margin note]]
Needles distance Deflect
1 .1th of an inch 0
2 .8 0
3 .4 1/2 +13°
4 .6 +18°
5 .7 1/2 +18°
6 .9 +19°
The softness of the needle gives it a more intense magnetism.
[[Line drawn across page]]
* Made some very small needles from the hair spring of a watch, arranged three of these above each other at the distance of 1/8 of an inch.
Needles distance Deflect Small [compass?]
1 1/8 +5°
2 1/4 0°
3 3/8 -1°
