On 2008/12/27, at 7:45 PM, Martin Vlietstra wrote:
The fraction 355/113 gives a better representation of pi (correct to 7
significant figures, not 3 significant figures (which is the
accuracy of
22/7)
Thanks Martin,
I've always enjoyed the number pattern implied in the value of pi that
you quote, 355/113, where the odd numbers in sequence from denominator
to numerator go 113 355, that I always remembered as 11 33 55.
I once, in the late 1960s, borrowed some (lunch) time on an ICL 3600
to run a Fortran program to find a better approximation of pi that
355/113 but I think, from memory, that I failed to find anything so
simple and elegant as 355/113.
Cheers,
Pat Naughtin
Geelong, Australia
P.S. To answer Jim's note a little better, it seems that I was brought
up believing that all circles had a radius that was a multiple of 7;
otherwise the approximation for pi, 22/7, would not calculate easily.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf
Of James Frysinger
Sent: 27 December 2008 01:16
To: U.S. Metric Association
Subject: [USMA:42211] Re: A pint's a pound the whole world round
You folks are squinting too hard.
Again, I think that this was never meant to be more than a rule of
thumb, a bit like "pi equals 22/7".
It's made a bit cuter by the fact that both a pint and a pound contain
16 ounces, albeit different kinds of ounces.
Jim
Jon Saxton wrote:
I never heard that rhyme until I read it on this list. I assume it
is
based on the idea that there are 16 ounces in a pound and 16 fluid
ounces in a pint. If a fluid ounce of something weighs one ounce
then
in a sense the pint and pound are equivalent. Of course it depends
on
what you fill the pint container with. A pint of naphtha would be
somewhat lighter than a pound, whereas a pint of mercury would be
much
heavier.
So what is the substance which makes the rhyming equation true? The
most likely candidate is water. So presumably the rhyme says 16 oz
of
water is a pint or a pound, "the whole world round".
I grew up in Australia using British pints of 20 oz so it would have
been plain wrong there and it is not surprising that the rhyme was
not
part of my culture. Only in the USA is the 16 oz pint used. Since
1824
the pint used in all other English-speaking countries was the 20 oz
pint
of my youth. The part that says "the whole world round" is simply
wrong.
Interestingly enough, the rhyme is wrong in the USA as well. A
pint is
simply not equivalent to a pound. The USA inherited the pint from
the
UK as it was at the end of the 18th century. The gallon of the
time was
the Queen Ann "wine gallon" of 1707 based on the volume of eight troy
pounds of wine. Because the USA seceded from the British Empire in
the
latter part of the 18th century it did not adopt the 1824 uniform
redefinition of the gallon as the volume occupied by 10 lb
(avoirdupois)
of distilled water (measured at 62ºF in air at a pressure of 30" of
mercury *). The British ounce of water by weight and by volume were
established as equivalent. The volume of a UK (Imperial) gallon
worked
out at a bit over 277 in³ or 4.55 L whereas the US gallon (i.e. the
old
wine gallon) was 231 in³ or 3.79 L. There are 160 fluid ounces to
the
Imperial gallon which, as mentioned above, preserves the water
weight/volume relationship. A UK fluid ounce is about 1.74 in³ or
28.4
ml. However the USA divides its gallon into 128 fluid ounces which
means each fl oz is about 1.80 in³ or 29.6 ml. So a US pint of 16 US
fluid ounces of water weighs about 4% more than a pound.
So the "whole world round" part is not true in the USA either. It is
just wrong everywhere^.
*Ref: R. D. Connor, _The Weights and Measures of England_, Science
Museum, London, 1987. ISBN 0 11 290435 1
^This discussion only addresses liquid measures. When we bring dry
pints into consideration then we have a whole new set of ways for the
rhyme to be wrong.
James Frysinger wrote:
I was fortunate in the 7th grade; our math teacher ignored the
school
board and taught us algebra. However in the 8th grade, we had a math
teacher who started off by saying that he hated math and was just
waiting until a coaching job came up at the high school (grades 9 to
12). The only thing I recall doing that year (apart from mischief)
was
spending untold hours memorizing U.S. customary weights and measures
tables and key facts, such as the number of square feet in an
acre. I
think the rest of the year must have been spent on arithmetic,
working
percentage and interest problems, for example.
One of the essential facts that we learned was "a pint's a pound the
whole world 'round" and my parents said they had learned that in
school, too. My recollection is that this was given as a "rule of
thumb" and not an exact conversion and one easy to memorize because
both a pint and a pound comprised 16 ounces (albeit of different
natures). So it was also a reinforcement of the facts that a pint
contains 16 fluid ounces and a pound avoirdupois contains 16 ounces
avoirdupois. Yes, we learned all about Troy pounds and ounces,
too. I
think our textbook in that 8th year had been published in 1811, just
before the British set fire to the White House. (I'm just kidding
about the publication date; the arson is fairly well accepted as
fact.)
By the way, my father and his brothers had the same teacher for
their
7th grade math classes and she taught them algebra, too. They
recalled
her as being old to the point of being ready for retirement at the
time they had her.
Jim
Pat Naughtin wrote:
Dear All,
I was looking for the origins of the maxim, 'A pint's a pound the
whole world round' when I happened on this reference at
http://makezine.com/16/diyhome_measure/#msg3308 where they say:
There's a difference between a U.S. pint (16 fl oz) and an Imperial
pint (20 fl oz), which means that a pint's a pound only in the USA.
An Imperial gallon of water weighs ten pounds, which means, (if
I've
got my old pre-metrication sums right) that a fluid ounce of water
weighs an ounce. Now, it seems that the U.S. gallon is also
different
from the U.S. gallon, which make sense.
Does anyone have any 'Rules of thumb' that apply to gallons,
quarts,
pints, and fluid ounces in the USA.
Cheers,
Pat Naughtin
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has
helped thousands of people and hundreds of companies upgrade to the
modern metric system smoothly, quickly, and so economically that
they
now save thousands each year when buying, processing, or selling
for
their businesses. Pat provides services and resources for many
different trades, crafts, and professions for commercial,
industrial
and government metrication leaders in Asia, Europe, and in the USA.
Pat's clients include the Australian Government, Google, NASA,
NIST,
and the metric associations of Canada, the UK, and the USA. See
http://www.metricationmatters.com
<http://www.metricationmatters.com/>for more metrication
information,
contact Pat at [email protected]
<mailto:[email protected]> or to get the free
'/Metrication matters/' newsletter go to:
http://www.metricationmatters.com/newsletter to subscribe.
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(C) 931.212.0267
(H) 931.657.3107
(F) 931.657.3108
Cheers,
Pat Naughtin
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has
helped thousands of people and hundreds of companies upgrade to the
modern metric system smoothly, quickly, and so economically that they
now save thousands each year when buying, processing, or selling for
their businesses. Pat provides services and resources for many
different trades, crafts, and professions for commercial, industrial
and government metrication leaders in Asia, Europe, and in the USA.
Pat's clients include the Australian Government, Google, NASA, NIST,
and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com
for more metrication information, contact Pat at [email protected]
or to get the free 'Metrication matters' newsletter go to: http://www.metricationmatters.com/newsletter
to subscribe.
