Here's a nice item I've had kicking around for a year (so I can't
thank whomever gave it to me) that I put on an overhead for my E&M
students before their exam this week. It connects Thanksgiving with
physics. As Doug Craigen has mentioned, Canadian Thanksgiving is
this coming Monday. It is our custom to celebrate it on Sunday
instead so our friends from south of the border can also join us.
We will have 17 for turkey this year. I don't plan to emulate what
is suggested herein by one of America's greatest physicists.
Leigh
(WARNING: The following material contains explicit
description of violence. Teacher discretion is advised.
The kids may love it. Animal rights types and militant
vegetarians will be pleased.)
The Thanksgiving Spirit (1750)
Dear Friend,
I have lately made an experiment that I desire never to
repeat. Two nights ago, being about to kill a turkey by
the shock from two large glass jars, containing as much
electrical fire as forty common phials, I inadvertently
took the whole through my own arms and body, by receiving
the fire from the united top wires with one hand while
the other held a chain connected with the outside of both
jars. The company present (whose talking to me and to
one another, I suppose, occasioned my inattention to what
I was about) say that the flash was very great, and the
crack as loud as a pistol, yet, my senses being instantly
gone, I neither saw the one nor heard the other; nor did
I feel the stroke in my hand, though afterwards found it
raised a round swelling where the fire entered, as big as
half a pistol bullet, by which you may judge the
quickness of the electrical fire, which by this instance
seems to be greater than that of sound, light, or animal
sensation.
What I can remember of the matter is that I was about to
try whether the bottles or jars were fully charged by the
strength and length to my hand, as I commonly used to do,
and which I might safely enough have done if I had not
held the chain in the other hand. I then felt what I
know not how to describe... a universal blow throughout
my whole body from head to foot, which seemed within as
well as without; after which the first thing I took
notice of was a violent quick shaking of my body, which
gradually remitting, my sense as gradually returned, and
then I thought the bottles must be discharged, but could
not conceive how, till at last I perceived the chain in
my hand, and recollected what I had been about to do.
That part of my hand and fingers which held the chain was
left white, as though the blood had been driven out, and
remained so eight or ten minutes after, feeling like dead
flesh; and I had a numbness in my arms and back of my
neck, which continued till the next morning, but wore
off. Nothing remains now of the shock but a soreness in
my breastbone, which feels as if it had been bruised. I
did not fall, but suppose I should have been knocked down
if I had received the stroke in my head. The whole was
over in a minute.
You may communicate this to Governor Bowdoin as a caution
to him, but do not make it more public, for I am ashamed
to have been guilty of so notorious a blunder; a match
for that of the Irishman whom my sister told me of, who,
to divert his wife, poured the bottle of gun powder on
the live coal; or that of the other, who, being about to
steal powder, made a hole in the cask with a hot iron.