| |
KF5JRV > TECH 27.10.16 03:33l 40 Lines 2275 Bytes #999 (0) @ WW
BID : 4206_KF5JRV
Read: GUEST
Subj: Vitreous Electricity
Path: IW8PGT<IR2UBX<IZ3LSV<ED1ZAC<NA7KR<KQ0I<N9LYA<N0KFQ<AE5ME<KF5JRV
Sent: 161026/1138Z 4206@KF5JRV.#NWAR.AR.USA.NA BPQK6.0.13
Vitreous Electricity, Conservation of Charge
Benjamin Franklin (1706-90) was an American printer, author, philosopher,
diplomat, scientist, and inventor.
After Gilbert's discovery that a force of electric charge is created by
friction of different materials, Benjamin Franklin in 1747, improved on
this by announcing that this electric charge exists of two types of electric
forces, an attractive force and a repulsive force. (William Watson (1715-87)
in England independently reached the same conclusion.) To identify these
two forces, he gave the names, positive and negative charges and to
symbolize them, he used the + and - signs the + being for positive and
the - for negative. Benjamin Franklin realized that all materials possess
a single kind of electrical "fluid" that can penetrate matter freely but
that can be neither created nor destroyed. The action of rubbing merely
transfers the fluid from one body to another, electrifying both. Franklin
and Watson originated the principle of conservation of charge: the total
quantity of electricity in an insulated system is constant. Franklin
defined the fluid, which corresponded to vitreous electricity, as positive
and the lack of fluid as negative. Therefore, according to Franklin, the
direction of flow was from positive to negative--the opposite of what is
now known to be true. A subsequent two-fluid theory was developed,
according to which samples of the same type attract, whereas those of
opposite types repel.
Franklin was acquainted with the Leyden jar (a glass jar coated inside and
outside with tinfoil), how it could store a charge and how it caused a
shock when it was discharged. Franklin wondered whether lightning and
thunder were also a result of electrical discharges. During a thunderstorm
in 1752, Franklin flew a kite that had a metal tip. At the end of the wet,
conducting hemp line on which the kite flew he attached a metal key, to
which he tied a nonconducting silk string that he held in his hand. The
experiment was extremely hazardous, but the results were unmistakable:
when he held his knuckles near the key, he could draw sparks from it.
The next two who tried this extremely dangerous experiment were killed.
73 Scott KF5JRV
KF5JRV.#NWAR.AR.USA.NA
Read previous mail | Read next mail
| |
