[[email protected]]

What is the kind of turntable called with the old big round needle
holder and pen tip-like needles? Apparently it is what I need to play
home recorded vinyl and/or most 10" 78's. I have forgetten what it is
called. Mostly I'm wondering if there are any of those types that have
any audio outputs, or if they just have built in speakers. I'd like to
record from it straight to my PC is possible.

[wß]

wrote:
What is the kind of turntable called with the old big round needle
holder and pen tip-like needles? Apparently it is what I need to play
home recorded vinyl and/or most 10" 78's. I have forgetten what it is
called. Mostly I'm wondering if there are any of those types that have
any audio outputs, or if they just have built in speakers. I'd like to
record from it straight to my PC is possible.

antique...







Just kidding. Victrola maybe?

[[email protected]]

Yeah, I think Victrola's use that, but so do other kinds...it's the
type of needle and cartridge that I'm looking for.

wß wrote:
wrote:
What is the kind of turntable called with the old big round needle
holder and pen tip-like needles? Apparently it is what I need to play
home recorded vinyl and/or most 10" 78's. I have forgetten what it is
called. Mostly I'm wondering if there are any of those types that have
any audio outputs, or if they just have built in speakers. I'd like to
record from it straight to my PC is possible.

antique...







Just kidding. Victrola maybe?

[Richard Crowley]

alice wrote ...
What is the kind of turntable called with the old big
round needle holder and pen tip-like needles?

Sounds like the old "acoustic" phonograph players where
the needle would move the round diaphragm on the end of
the tone arm, and the sound would go down the arm and
into a big horn ("mechanical" amplification).

Apparently it is what I need to play home recorded vinyl
and/or most 10" 78's.

No, the acoustic phonographs were just the "state of the art"
~100 years ago. It doesn't mean that is what you need to
play it today. You just need to use a modern turntable with
the right size/type of stylus for the particular disc. There
are people on these newsgroups who are experts at this,
like Scott Dorsey.

Note that playing those old discs is not as strightforward
as playing a black-vinyl 33rpm LP disc. If you don't use
the right stylus, cleaning, etc. you could permanently
destroy the recording (and/or the equipment).

[Mark D. Zacharias]

Richard Crowley wrote:
alice wrote ...
What is the kind of turntable called with the old big
round needle holder and pen tip-like needles?

Sounds like the old "acoustic" phonograph players where
the needle would move the round diaphragm on the end of
the tone arm, and the sound would go down the arm and
into a big horn ("mechanical" amplification).

Apparently it is what I need to play home recorded vinyl
and/or most 10" 78's.

No, the acoustic phonographs were just the "state of the art"
~100 years ago. It doesn't mean that is what you need to
play it today. You just need to use a modern turntable with
the right size/type of stylus for the particular disc. There
are people on these newsgroups who are experts at this,
like Scott Dorsey.

Note that playing those old discs is not as strightforward
as playing a black-vinyl 33rpm LP disc. If you don't use
the right stylus, cleaning, etc. you could permanently
destroy the recording (and/or the equipment).

Any turntable with the 78 R.P.M. speed would do, and there are more modern
cartidges with appropriate stylii available for 78's.

You may need to account for different equalizations, though it seems to me
that was early LP's, not 78's.

Mark Z.

[Goaty]

Richard Crowley wrote:

alice wrote ...

What is the kind of turntable called with the old big round needle
holder and pen tip-like needles?

Apparently it is what I need to play home recorded vinyl and/or most
10" 78's.


No, the acoustic phonographs were just the "state of the art"
~100 years ago. It doesn't mean that is what you need to
play it today. You just need to use a modern turntable with
the right size/type of stylus for the particular disc. There
are people on these newsgroups who are experts at this, like Scott Dorsey.

Note that playing those old discs is not as strightforward
as playing a black-vinyl 33rpm LP disc. If you don't use
the right stylus, cleaning, etc. you could permanently
destroy the recording (and/or the equipment).

Get out a DVD called Desperate Man Blues - a biopic of an amazing 78rpm
blues record collector. He discusses this in simple language. I'm not so
impressed with his disk cleaning technique ... see deleted scenes.

Cheers
Goaty
--
_--_|\ John Lamp - in beautiful downtown Highton
/ \ DoD#:1906 Ulysses#:10185 Vulcan Nomad
\_.--._/ Phone: 0409 512 254
v Hear no Evo, See no Evo, Fear no Evo

Militant Agnostic - I don't know and you don't either

[Eeyore]

wrote:

Yeah, I think Victrola's use that, but so do other kinds...it's the
type of needle and cartridge that I'm looking for.

Is this a joke / troll ?

There is no cartridge ( or indeed any electronics ) in these.

You can record it using a microphone of course.

Graham

[Richard Crowley]

"Mark D. Zacharias" wrote ...
Any turntable with the 78 R.P.M. speed would do, and
there are more modern cartidges with appropriate stylii
available for 78's.

Right. Never try playing a 78 with an LP stylus.

You may need to account for different equalizations,
though it seems to me that was early LP's, not 78's.

Other way around. CBS's 33-1/3 RPM "LP" format
tended to also standardize the EQ as I recall.

OTOH, There were dozens (or more?) different
EQ curves used for cutting 78s. Modern preamps
made for playing 78s have several selections for
various EQ settings.

[Mr.T]

"Richard Crowley" wrote in message
...
You may need to account for different equalizations,
though it seems to me that was early LP's, not 78's.

Other way around. CBS's 33-1/3 RPM "LP" format
tended to also standardize the EQ as I recall.

OTOH, There were dozens (or more?) different
EQ curves used for cutting 78s. Modern preamps
made for playing 78s have several selections for
various EQ settings.

That's the least of the problems, since you can re-adjust equalisation to
suit in any good wave editor *after* the recording is made.
There may be a better choice to start with than standard RIAA, but that's
probably the easiest place to start for most people.

MrT.

[Paul Stamler]

"Richard Crowley" wrote in message
...
"Mark D. Zacharias" wrote ...
Any turntable with the 78 R.P.M. speed would do, and
there are more modern cartidges with appropriate stylii
available for 78's.

Right. Never try playing a 78 with an LP stylus.

You may need to account for different equalizations,
though it seems to me that was early LP's, not 78's.

Other way around. CBS's 33-1/3 RPM "LP" format
tended to also standardize the EQ as I recall.

Not really; there were a whole bunch of different curves to play 33's,
including the LP curve (Columbia), the NAB curve, the AES curve, the FFRR
curve, a couple that only applied to one or two small labels. Then there was
the curve RCA Victor used, which in 1955 became standardized as the RIAA
curve.

OTOH, There were dozens (or more?) different
EQ curves used for cutting 78s. Modern preamps
made for playing 78s have several selections for
various EQ settings.

Yup. Basically there were about half a dozen rolloff frequencies for the
treble and an equal number of transition frequencies from midrange to bass.
Some of the latter specified a third frequency in the bass where the curve
would stop rising; others didn't. Lots and lots of possibilities. Ideally
you choose the treble and bass curves independently for playback.

To the original poster: you do *not* want an acoustic phonograph for playing
your 78s, and evern more emphatically you do not want one for playing home
transcriptions. Not with the typical acoustic phonograph tracking force of
several ounces (as opposed to a few grams with a modern turntable); an
acoustic phonograph will grind a home transcription to nothing.

Peace,
Paul

[William Sommerwerck]

OTOH, There were dozens (or more?) different EQ
curves used for cutting 78s. Modern preamps made
for playing 78s have several selections for various
EQ settings.

I'm not an expert on 78 EQ. However, there _were_ multiple LP EQs -- each
major label had its own, and preamps offered multiple curves. In fact, some
even had separate turnover and rolloff switches! The RIAA curve in 1954
ended this silliness.

[Serge Auckland]

William Sommerwerck wrote:
OTOH, There were dozens (or more?) different EQ
curves used for cutting 78s. Modern preamps made
for playing 78s have several selections for various
EQ settings.

I'm not an expert on 78 EQ. However, there _were_ multiple LP EQs -- each
major label had its own, and preamps offered multiple curves. In fact, some
even had separate turnover and rolloff switches! The RIAA curve in 1954
ended this silliness.


Correct. Until the RIAA sorted it in 1954, there were at least the
following being used:-

Am. Col.
AES
NAB
NARTB (slightly different from NAB)
RCA new and old
Decca
HMV & Brit. Col (used same characteristic)
Nixa (two different characteristics were used)
DGG (used the same characteristics for LPs as they did for 78s)

If anyone's interested, I can send them the characteristics for the above.

S.

[Mark D. Zacharias]

Richard Crowley wrote:
"Mark D. Zacharias" wrote ...
Any turntable with the 78 R.P.M. speed would do, and
there are more modern cartidges with appropriate stylii
available for 78's.

Right. Never try playing a 78 with an LP stylus.

You may need to account for different equalizations,
though it seems to me that was early LP's, not 78's.

Other way around. CBS's 33-1/3 RPM "LP" format
tended to also standardize the EQ as I recall.

OTOH, There were dozens (or more?) different
EQ curves used for cutting 78s. Modern preamps
made for playing 78s have several selections for
various EQ settings.

I wondered about that - but I was thinking that using the earliest acoustic
recording and playback techniques, equalization as we think of it today
would have been impossible (?). I knew there were various EQ curves which
predated the RIAA standard, just didn't know when they came into the
picture.

Mark Z.

[Scott Dorsey]

In article ,
Richard Crowley wrote:
alice wrote ...
What is the kind of turntable called with the old big
round needle holder and pen tip-like needles?

Sounds like the old "acoustic" phonograph players where
the needle would move the round diaphragm on the end of
the tone arm, and the sound would go down the arm and
into a big horn ("mechanical" amplification).

Apparently it is what I need to play home recorded vinyl
and/or most 10" 78's.

No, the acoustic phonographs were just the "state of the art"
~100 years ago. It doesn't mean that is what you need to
play it today. You just need to use a modern turntable with
the right size/type of stylus for the particular disc. There
are people on these newsgroups who are experts at this,
like Scott Dorsey.

Note that playing those old discs is not as strightforward
as playing a black-vinyl 33rpm LP disc. If you don't use
the right stylus, cleaning, etc. you could permanently
destroy the recording (and/or the equipment).

I didn't see the original post, but I will say that there were some
electrical pickups with steel needles which were popular in the early
1930s before jeweled pickups completely took over. They destroy records.

If you want to play home recordings, your goal is to get as light tracking
force as possible because the material is so soft. Acoustic phonographs
have tracking forces measured in KILOGRAMS, not in grams. This is not
good for records.

If the original poster is looking to play back 78s, she would be good
to look at a Thorens 126, which shows up reasonably priced on the used
market. Combine this with a Grado DJ-100 cartridge with the 2.7 mil
78 stylus. This isn't optimal for most 78s and it is WAY off for acoustic
discs, but it's serviceable and it won't ruin records. Add the Re-Equalizer
from Esoteric Sound to help you get the emphasis right... 78s predate the
modern RIAA standard emphasis curve so there is always some tweaking involved.
you should be able to find a complete system for around $800 if you shop
around and buy the turntable used.

The next step up would be to buy a cartridge with a wide variety of different
sized styli. This can be a huge improvement in tracking distortion and
allow you to play a lot more different kinds of records properly, but it
costs you.

For most 78s you can just wash them in a good detergent cleaner like
Alconox and towel them down. A higher grade ultrasonic machine helps
but isn't absolutely necessary.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Mark D. Zacharias wrote:

I wondered about that - but I was thinking that using the earliest acoustic
recording and playback techniques, equalization as we think of it today
would have been impossible (?). I knew there were various EQ curves which
predated the RIAA standard, just didn't know when they came into the
picture.

They pretty much came into the picture at the beginning of the electrical
recording era. Folks started using emphasis in order to make records
sound better as soon as they possibly could.

Acoustics are another ball of wax. Acoustics have all sorts of interesting
mechanical and acoustical resonances in the recording process, and how to
deal with them often becomes a religious issue because it can be hard to
tell what is part of the singer's voice and what is part of the horn. I
won't touch acoustics myself, but I know plenty of folks who work with them
and it's very subjective work.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

Scott Dorsey wrote:
If you want to play home recordings, your goal is to get as light tracking
force as possible because the material is so soft. Acoustic phonographs
have tracking forces measured in KILOGRAMS, not in grams.

Actually, to be precise, forces are NEVER measured either in
kilograms or grams, with very few exceptions, the turntable business
being one of them. Kilograms and grams are not units of force,
they're units of mass. Force is measured in netwons or dynes.

The confusion comes from the fact that a mass exhibits a down
ward force due to gravity that's proportional to its mass. Zero-
balance a tone arm, out one grams of mass at the stylus, and
now you have an unbalanced force at the stylus of 1 g * 980cm/sec^2
or 980 dynes.

[Scott Dorsey]

wrote:
Scott Dorsey wrote:
If you want to play home recordings, your goal is to get as light tracking
force as possible because the material is so soft. Acoustic phonographs
have tracking forces measured in KILOGRAMS, not in grams.

Actually, to be precise, forces are NEVER measured either in
kilograms or grams, with very few exceptions, the turntable business
being one of them. Kilograms and grams are not units of force,
they're units of mass. Force is measured in netwons or dynes.

But we can use ounces and pounds to measure both! But then, you can
also measure fluid volume with ounces...
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

Scott Dorsey wrote:

Actually, to be precise, forces are NEVER measured either in
kilograms or grams, with very few exceptions, the turntable business
being one of them. Kilograms and grams are not units of force,
they're units of mass. Force is measured in netwons or dynes.

But we can use ounces and pounds to measure both!

Actually, we don't. When you buy a pound of flour, you're
buying the equivalent mass that results in 1 lbf (pound-force).

The problem being is that the imperial system of units is
grossly inconsistent, and "pounds" can mean any number of
things. Try to use the inconsistencies in equations, and you
get nonsensical answers.

But, to repeat, gram and kilogram are NOT units of force, they're
units of mass. Forces are measured in dynes and newtons.
"Weighing" means measuring force. Take 1 gram of mass
say a piece of water at about 4C measuring 1cmx1cmx1cm
and weigh it at the equator, and weigh it near the poles: you
will get two different, albeit small, answers, because the
net acceleration of gravity is different in these two places.
Now, weigh it on the moon, and you get something radically
different. Yet, it's still a 1 gram mass.

But then, you can
also measure fluid volume with ounces...

That would be "floz" vs "oz", of course. :-)

[Scott Dorsey]

wrote:
Scott Dorsey wrote:

Actually, to be precise, forces are NEVER measured either in
kilograms or grams, with very few exceptions, the turntable business
being one of them. Kilograms and grams are not units of force,
they're units of mass. Force is measured in netwons or dynes.

But we can use ounces and pounds to measure both!

Actually, we don't. When you buy a pound of flour, you're
buying the equivalent mass that results in 1 lbf (pound-force).

But we measure gas pressure in psi or lbs/inch^2 if you prefer.
Not pfsi.
--scott

Don't mind me, I'm just being picky today. But it's true that the old
standard system is very sloppy about this, which is fine as long as you
aren't working with both mass and force at the same time.
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Paul Stamler]

"Scott Dorsey" wrote in message
...

Acoustics are another ball of wax. Acoustics have all sorts of
interesting
mechanical and acoustical resonances in the recording process, and how to
deal with them often becomes a religious issue because it can be hard to
tell what is part of the singer's voice and what is part of the horn. I
won't touch acoustics myself, but I know plenty of folks who work with
them
and it's very subjective work.

Boy, ain't that the truth. I just got done restoring 49 acoustic recordings,
and it was a wild ride. I made the decision, early on, that I wasn't going
to try to mess with those little resonances, and it was still a highly
subjective exercise. Yow. Fun, though (good music).

Peace,
Paul

[Eeyore]

wrote:

Scott Dorsey wrote:
If you want to play home recordings, your goal is to get as light tracking
force as possible because the material is so soft. Acoustic phonographs
have tracking forces measured in KILOGRAMS, not in grams.

Actually, to be precise, forces are NEVER measured either in
kilograms or grams, with very few exceptions, the turntable business
being one of them. Kilograms and grams are not units of force,
they're units of mass. Force is measured in netwons or dynes.

The confusion comes from the fact that a mass exhibits a down
ward force due to gravity that's proportional to its mass. Zero-
balance a tone arm, out one grams of mass at the stylus, and
now you have an unbalanced force at the stylus of 1 g * 980cm/sec^2
or 980 dynes.

Why are you using old cgs units ?

Using SI that's 1*10^-3 kg * 9.81 ms^-2 = 9.81 mN :-)


Graham

[[email protected]]

Scott Dorsey wrote:
wrote:
Scott Dorsey wrote:

Actually, to be precise, forces are NEVER measured either in
kilograms or grams, with very few exceptions, the turntable business
being one of them. Kilograms and grams are not units of force,
they're units of mass. Force is measured in netwons or dynes.

But we can use ounces and pounds to measure both!

Actually, we don't. When you buy a pound of flour, you're
buying the equivalent mass that results in 1 lbf (pound-force).

But we measure gas pressure in psi or lbs/inch^2 if you prefer.
Not pfsi.

No, "we" measure gas pressure in pascals. My dausghter just
finished her third year in mechanical engineering with the hydraulics
and pneumatics course. Coincidentally, she saw a sprinkler pipe
burst at the bottom of a 10 story building, and was thorouoghly
impressed with the display. SHe's abosultely aced every math
course she took blindfolded, but in trying to calculate in her head
what the pressures and likely volumes involved were, sho got
herself thoroughly tied in knots trying to do it in lbs and feet and
such,
and did it in about 3 seconds when she switched to SI.

Don't mind me, I'm just being picky today. But it's true that the old
standard system is very sloppy about this, which is fine as long as you
aren't working with both mass and force at the same time.

Which many people dealing with turntables do and end up
coming to bogus conclusions. For example, they often
assume that adjusting the counterweight to add "1 gram"
of tracking force increases the moving mass of the tone
arm by one gram. In fact, it reduces the moving mass
somewhat.

[Eeyore]

Scott Dorsey wrote:

wrote:
Scott Dorsey wrote:

Actually, to be precise, forces are NEVER measured either in
kilograms or grams, with very few exceptions, the turntable business
being one of them. Kilograms and grams are not units of force,
they're units of mass. Force is measured in netwons or dynes.

But we can use ounces and pounds to measure both!

Actually, we don't. When you buy a pound of flour, you're
buying the equivalent mass that results in 1 lbf (pound-force).

But we measure gas pressure in psi or lbs/inch^2 if you prefer.
Not pfsi.
--scott

Don't mind me, I'm just being picky today. But it's true that the old
standard system is very sloppy about this, which is fine as long as you
aren't working with both mass and force at the same time.

For the very brief time I ever used it, it used to drive me nuts. Thank heavens
for MKS and then SI.

There's poundals too btw.

Graham

[Ron Capik]

Scott Dorsey wrote:

wrote:
Scott Dorsey wrote:
If you want to play home recordings, your goal is to get as light tracking
force as possible because the material is so soft. Acoustic phonographs
have tracking forces measured in KILOGRAMS, not in grams.

Actually, to be precise, forces are NEVER measured either in
kilograms or grams, with very few exceptions, the turntable business
being one of them. Kilograms and grams are not units of force,
they're units of mass. Force is measured in netwons or dynes.

But we can use ounces and pounds to measure both! But then, you can
also measure fluid volume with ounces...
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

If we keep poundal-ing this topic it could turn in to a slug fest,
though there may be a grain of truth here.

Later...

Ron Capik
--

[Scott Dorsey]

wrote:

No, "we" measure gas pressure in pascals. My dausghter just
finished her third year in mechanical engineering with the hydraulics
and pneumatics course. Coincidentally, she saw a sprinkler pipe
burst at the bottom of a 10 story building, and was thorouoghly
impressed with the display. SHe's abosultely aced every math
course she took blindfolded, but in trying to calculate in her head
what the pressures and likely volumes involved were, sho got
herself thoroughly tied in knots trying to do it in lbs and feet and
such,
and did it in about 3 seconds when she switched to SI.

It's way worse than that. I work with some folks who, in the same
control room, use psi, psf, kg/cm3, inches of water, inches of mercury,
millimeters of mercury, millibars, pascals, and torr.

But if she got around 250 psi, that would seem about typical.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Scott Dorsey wrote:

It's way worse than that. I work with some folks who, in the same
control room, use psi, psf, kg/cm3, inches of water, inches of mercury,
millimeters of mercury, millibars, pascals, and torr.

Oh, yes, and that psi could either be psia or psig depending on the
measurement... and there's at least one thing calibrated just in "atmospheres"
too...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Rusty B.]

wrote:
Okay, then I ask, why don't the trunks of giant sequoia trees
explode under the pressure of the sap?

Transpiration and adhesive intermolecular forces?

[James Lehman]

Edison invented the phonograph, but he go one thing a bit wrong. He cut
vibrations perpendicular to the surface of the record (up and down), whereas
Victor figured out how to cut the vibrations laterally (side to side).
Victors idea was eventually adapted to make stereo records possible by
altering the angles a bit so that the surfaces of the grove would be at 90
degrees of each other and left and right signals could be distinguished as
twist on the cantilever in two different planes.

James. )




wrote in message
oups.com...
What is the kind of turntable called with the old big round needle
holder and pen tip-like needles? Apparently it is what I need to play
home recorded vinyl and/or most 10" 78's. I have forgetten what it is
called. Mostly I'm wondering if there are any of those types that have
any audio outputs, or if they just have built in speakers. I'd like to
record from it straight to my PC is possible.

[Paul Stamler]

wrote in message
ups.com...

Okay, then I ask, why don't the trunks of giant sequoia trees
explode under the pressure of the sap?

They do, just like maple trees -- didn't you hear NPR's expose of that a
year ago April?

Peace,
Paul

[Arny Krueger]

wrote in message
ups.com
Scott Dorsey wrote:
wrote:
She's absolutely aced every math
course she took blindfolded, but in trying to calculate
in her head what the pressures and likely volumes
involved were, sho got herself thoroughly tied in knots
trying to do it in lbs and feet and such, and did it
in about 3 seconds when she switched to SI.

It's way worse than that. I work with some folks who,
in the same control room, use psi, psf, kg/cm3, inches
of water, inches of mercury, millimeters of mercury,
millibars, pascals, and torr.

But if she got around 250 psi, that would seem about
typical.

Well, the fun began when I asked her to compare the fluid
pressure effects in a 30-story high-rise building. Call
it 300 feet. Very quickly,
I figured static water column pressure of 9 atmospheres.
Why? Standard atmosphere is 0.76 meters mercury column.
Mercury
is some 13 times denser than water, so equivalent water
column
is 13 times 0.76 meters or 9.88 meters, damned near 33
feet.
so a 300 foot tall building with a pipe filled with water
will have, static, 9 atmospheres (300/33) of pressure at
the bottom.

You might blame the following on the fact that my 8th grade science teacher
was a skin diver, but here's the answer done simply and purely in U.S.
weights and measures:

A cubic foot of water weighs about 63 pounds. Divide by 144 to get 0.44
PSI. Multiply by height in feet to obtain pressure for water column that
height.

300* 0.44 = 131 PSI = about 8.9 atmospheres

[Scott Dorsey]

wrote in message

Well, the fun began when I asked her to compare the fluid pressure effects
in a 30-story high-rise building. Call it 300 feet. Very quickly, I figured
static water column pressure of 9 atmospheres. Why? Standard atmosphere is
0.76 meters mercury column. Mercury is some 13 times denser than water,
so equivalent water column is 13 times 0.76 meters or 9.88 meters, damned
near 33 feet.
so a 300 foot tall building with a pipe filled with water
will have, static, 9 atmospheres (300/33) of pressure at
the bottom.

Sure, but "A pint a pound the world around" and a a gallon is a little less
than eight cubic feet, so figure 64 lbs for a cubic foot of water. 12
inches per foot, 144 square inches per square foot, so a column a foot high
exerts a force of .44 lbs on every square inch. 300 feet tall gives you
132 psig at the base, one atmosphere is 14.7psi, so that's nine atmospheres.
No need to worry about how much mercury weighs or anything.

And as for why a redwood doesn't explode, I bet if you cut all the needles
off it suddenly, it would.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Ron Capik]

Scott Dorsey wrote:

wrote in message

Well, the fun began when I asked her to compare the fluid pressure effects
in a 30-story high-rise building. Call it 300 feet. Very quickly, I figured
static water column pressure of 9 atmospheres. Why? Standard atmosphere is
0.76 meters mercury column. Mercury is some 13 times denser than water,
so equivalent water column is 13 times 0.76 meters or 9.88 meters, damned
near 33 feet.
so a 300 foot tall building with a pipe filled with water
will have, static, 9 atmospheres (300/33) of pressure at
the bottom.

Sure, but "A pint a pound the world around" and a a gallon is a little less
than eight cubic feet, so figure 64 lbs for a cubic foot of water. 12
inches per foot, 144 square inches per square foot, so a column a foot high
exerts a force of .44 lbs on every square inch. 300 feet tall gives you
132 psig at the base, one atmosphere is 14.7psi, so that's nine atmospheres.
No need to worry about how much mercury weighs or anything.

And as for why a redwood doesn't explode, I bet if you cut all the needles
off it suddenly, it would.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Or, from SCUBA basics, one atmosphere is about 33 feet
in fresh water, a bit less in salt water.

Later...

Ron Capik
--

[Chris Morriss]

In message , Scott Dorsey
writes
wrote in message

Well, the fun began when I asked her to compare the fluid pressure effects
in a 30-story high-rise building. Call it 300 feet. Very quickly, I figured
static water column pressure of 9 atmospheres. Why? Standard
atmosphere is
0.76 meters mercury column. Mercury is some 13 times denser than water,
so equivalent water column is 13 times 0.76 meters or 9.88 meters, damned
near 33 feet.
so a 300 foot tall building with a pipe filled with water
will have, static, 9 atmospheres (300/33) of pressure at
the bottom.

Sure, but "A pint a pound the world around" and a a gallon is a little less
than eight cubic feet, so figure 64 lbs for a cubic foot of water. 12
inches per foot, 144 square inches per square foot, so a column a foot high
exerts a force of .44 lbs on every square inch. 300 feet tall gives you
132 psig at the base, one atmosphere is 14.7psi, so that's nine atmospheres.
No need to worry about how much mercury weighs or anything.

And as for why a redwood doesn't explode, I bet if you cut all the needles
off it suddenly, it would.
--scott



Apart from the fact that in most of the English speaking world, a pint
is 20 fluid ounces rather than the 18th century 16 fluid ounces that the
Americans stayed with. (Quaint people these 'Merkins!)
--
Chris Morriss

[Eiron]

Scott Dorsey wrote:

Sure, but "A pint a pound the world around" and a a gallon is a little less
than eight cubic feet,

A gallon is a lot less than eight cubic feet.

--
Eiron

No good deed ever goes unpunished.

[Scott Dorsey]

Chris Morriss wrote:

Apart from the fact that in most of the English speaking world, a pint
is 20 fluid ounces rather than the 18th century 16 fluid ounces that the
Americans stayed with. (Quaint people these 'Merkins!)

It's just part of an English conspiracy to get more beer.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Carey Carlan]

Eiron wrote in :

Scott Dorsey wrote:

Sure, but "A pint a pound the world around" and a a gallon is a
little less than eight cubic feet,

A gallon is a lot less than eight cubic feet.

He meant an eighth of a cubic foot.

[jakdedert]

Carey Carlan wrote:
Eiron wrote in :

Scott Dorsey wrote:

Sure, but "A pint a pound the world around" and a a gallon is a
little less than eight cubic feet,
A gallon is a lot less than eight cubic feet.

He meant an eighth of a cubic foot.

I believe that would be 0.8 cubic feet.

Eight cubic feet would be a two foot cube: 2'x 2'x 2'...wouldn't fit in
my fridge.

jak

[[email protected]]

jakdedert wrote:
Carey Carlan wrote:
Eiron wrote in :

Scott Dorsey wrote:

Sure, but "A pint a pound the world around" and a a gallon is a
little less than eight cubic feet,
A gallon is a lot less than eight cubic feet.

He meant an eighth of a cubic foot.

I believe that would be 0.8 cubic feet.

No, it wouldn't.

A gallon is 3.8 liters. A cubic foot is 28.3 liters. Therefore
there are 28.3/3.8 or just about 7.5 gallons per cubic foot.
That means a gallon is 1/7.5 gallons/ft^3 or 0.13 cubic
feet per gallon.

And since a liter of water is 1000 cm^3 of water, and
a cc of water is 1 gram, therefor a liter of water is 1000 kg.
And since there are 28.3 liters per ft^3, the mass of a
cubic foot, or 28.3 liters of water is 28.3 kg.

And since a mass of 1kg exerts a force due to gravity of
2.2 lbs, 28.3 kg of water, at the earth's surface exerts a
force due to gravity (or "weighs") 2.2 lbs/kg times 28.3 kg
or 62.3 lbs.

Q.E.D


Eight cubic feet would be a two foot cube: 2'x 2'x 2'...wouldn't fit in
my fridge.

[Karl Uppiano]

And as for why a redwood doesn't explode, I bet if you cut all the needles
off it suddenly, it would.

The water in a redwood is not standing in a column. It permeates the tissue
by capillary action (surface tension), and intermingles with the tree's very
strong structural fibers.

[Don Pearce]

On 8 Jul 2006 13:46:48 -0700, wrote:


A gallon is 3.8 liters. A cubic foot is 28.3 liters. Therefore
there are 28.3/3.8 or just about 7.5 gallons per cubic foot.
That means a gallon is 1/7.5 gallons/ft^3 or 0.13 cubic
feet per gallon.

No, you are thinking of those mean, short-measure US gallons. A *real*
gallon of water weighs 10 pounds. And there are 4.546 litres (*not*
liters) in a gallon. There are 0.16 cubic feet per gallon.

d

--
Pearce Consulting
http://www.pearce.uk.com