"B. Joshua Rosen" wrote:

On Fri, 27 Jun 2003 11:01:35 -0400, DigitalVinyl wrote:

Repeating Decimal wrote:

in article , David
Hare-Scott at wrote on 6/26/03 4:37 PM:


"Repeating Decimal" wrote in message
...
The five gallon containers for plants always seemed small to me. Today
I got
to measure one of them. When I calculated the volume, it was 3.4
gallons not
five. Am I missing something? Is there a arcane standard for this?

Bill


This seems a large discrepancy even for a container not selling product
by volume. Which gallon (USA or Imperial) does the container use? How
did you do the sums to work out your figure?

David


I used the US gallon which is the smallest on my calculator. I US gallon
is 231 cubic inches.

The formula I derived, although it should be available in reference
books, is:

V = (pi/3)*H*(R^2 +R*r+r^2).

H is the height of the conical frustum representing the shape of the
container. R and r are the upper and lower radii. H= 12 inches. R and r
are each *half* of the diameters 9.75 and 8.5 inches respectively. Out
comes 3.4Gal.

Your formula's correct. I imagine it is mostly blatant marketing
lies...much like the fact that monitors would measure 15" but only be
13.5" while a 19" TV is always 19".

DiGiTAL_ViNYL (no email)

A 19" TV has the same viewing area as a 19" monitor,
No, this hasn't been true- a class action lawsuit was filed and won
against computer monitor manufacturers due to this.

new SONY 36" HDTV = 36" viewable
15yr old 19" TV = 19" viewable
25yr old 19" TV = 19" viewable
5yr old 21" no-name = 20" viewable
7yr old 17" Nokia = 15.7" viewable
12yr old 16" Nanao = 14.5" viewable

TVs are always accurate take a tape measure into a electronics store.
Monitors used to be sold as 13,14,15,17,19,21 inches. Now you will
see 15.9",18.1",20.1" these are formerly 17", 19", 21" monitors. They
now show overly accurate sizes because for years they out and out
lied. Viewable areas were as much as 2 inches smaller than stated. I
got a check for a couple of bucks from the class action lawsuit
regarding this. woo-hoo!

the convention of
defining a CRT based on the maximum diameter of the tube itself rather
than the actual size of the picture arose with TVs.
In my short lifetime Tvs have been accurate. CRTs were the only ones
with discrepancies. In the last 15 years that I've bought TVs they
have always been
Once something becomes
an industry standard you can't change it even if it's widely regarded as
wrong. Assuming that the OP is correct and that a 5 gallon pot is really
3.4 gallons then there is probably some rational explanation for this
buried deep in the mists of time. If a pot were cylindrical rather than
conical then maybe a pot with the same diameter as the mouth of the
conical pot would hold 5 rather than 3.4 gallons (I haven't done the
calculation but it feels right). As another poster pointed out, plants are
sold in pots not dirt so their is no fraud involved. Dirt is sold in cubic
feet or yards not in gallons.
Eliminating the slope from the pot will increase its volume only to
3.89 gallons. To get this 12" high pot to hold 5 Gallons you would
have to increase its height to 18" tall. More than a slight change. I
actually found "five gallon" pots on the net that were even smaller
than this... they only hold 2.21 gallons.

I bought planters online and when they said they were 22qt..they were
22 qt... 8 gallons was 8 gallons...But then they don't sell 5 gallon
pots. They sell a 11" pot that holds 2 gallons.

DiGiTAL_ViNYL (no email)