I strongly support the idea of the glass database, and I mostly agree with the
opinions expressed by George Miller.  However, I would like to add a few comments
to George's discussion on the database idea.

 According to Glass Containers 1964, published by the
> Glass Container Manufacturers Institute, the average soft drink bottle
> made 22 trips for refilling before being broken or discarded (page 7).
>  The same report stated that the average milk bottle made 30 trips and
> the average beer bottle made 26 trips before breaking or being
> discarded.

The number of trips varies according to time period (bottles were much
 thicker in 1902 than in 1950) and size (6-ounce bottles survived more round trips
than quarts).  A pooled knowledge of round trips could lead to more
understanding about deposition lag in returnable bottles of the three
major types (dairy, soda, beer).

   In the late 1950s when I was a bag boy in a small local
> grocery store, one of our jobs was to sort pop bottles for pickup by
> the various venders.   We had a running game of who could find the
> Coke bottle from the farthest location.  We commonly had bottles from
> California, Texas, and other distant locations.  Some collectors of
> Coke bottles attempt to acquire bottles from all of the states.  The
> Coca Cola Company is aware of this and their special non-returnable
> small classic shape Coke bottles brought out at Christmas time are now
> marked with different states on the bottom which have nothing to do
> with where the bottles were made. Last year I purchased a six- pack of
> these disposable bottles, and the bottles had six different states on
> them.  This seems to b a rather crass appeal to Coke bottle collectors
> and putting information on the bottle that has no relationship as to
> where the Coke was bottled.  Clearly, using the information on a Coke
> bottle for studying regional and national markets is fraught with
> difficulties and problems.  In summary, private mold bottles for
> identifiable products with non-reused bottles have a great potential
> for looking at regional and national markets.

 Prior to 1965 (if my memory is correct), when the random city labeling
began, city/state designation on Coke bottles was a reliable source for
assessing distribution.

>       Beyond private and stock molds there are other types of
>       information
> available from markings on bottles that would be useful to gather into
> a database because they have good potential to provide chronological
> information.  Machine-made bottles are clearly going to be the clock
> for dating twentieth century sites.  This is an area where much can be
> done to provide tighter dates than are available for any other time
> period we deal with.  Here is a list of some of the possible things
> that would be worth recording.
>
> Bottle mold numbers
>
>       Almost all glass factories used bottle mold numbers as a way of
> keeping track of their inventories and to help customers order
> bottles. Surviving glassmakers' catalogs provide commonly provide the
> size and name and an illustration of their bottles along with the mold
> numbers. Compiling a list of the mold numbers along with the names of
> the bottle type and size would provide an excellent tool for
> identification of bottles and their makers.  The problem is that
> different glass factories use the same numbers. This is especially
> true for three digit numbers.  Thus if you have three bottles with
> only the number "50" embossed on their base and they are quite
> different in shape and size, it is impossible to know who made the
> bottle.  However, the systematic gathering of mold number with
> descriptions from catalogs could increase our ability to identify and
> date bottles.  Bottle mold number information has already been
> compiled for Canadian glass companies from company catalogs.  (Miller
> and Jorgensen 1986).

 Some of the earlier mold numbers include date codes.  Mike Miller and I
 are currently working on the date codes used on ca. 1916-1930 soda bottles in
Southern New Mexico.  The dates we are finding are consistent with known
use periods of the bottles in our area.  These should generalize.
>
> Date codes
>
>       Several of the glass companies used date codes that are
>       generally
> described in Toulouse.  In some cases such as Owens-Illinois Glass
> Company the date code is a one-digit number to the right of the
> trademark.  Thus if you have a "3" in that position the bottle could
> be from 1933, 1943 or 1953.  The date code can often be used with
> other characteristics of the bottle to begin to eliminate some of the
> numbers.  For example, if the "3" is on a cork stopped bottle, it
> probably predates WWII and thus would have been made in 1933.  Date
> code numbers should be included in any database recording system.

My empirical research suggests that you can tell the difference between
 the decades.  Beginning in 1940, a dot was placed behind the single-digit
number.  This system was used fairly consistently until 1945, when Owens
Illinois went to a two- digit number.  Thus a 1 = 1931; a 1. = 1941; and
51 = 1951.  A dot was still occasionally used for 1945 and 1946 bottles.
(see Lockhart 2000, chapter 2
http://alamo.nmsu.edu/~lockhart/EPSodas/index.html)
>
> Glass color
>
>       The movement toward colorless glass is an area where there is
>       good
> potential for improving our ability to date bottles.  One area that
> has received a lot of attention is that of solarized glass.  This
> glass was made colorless by the addition of manganese to the glass
> batch to overcome the slight green color from iron in the glass
> (Miller and Pacey 1985:44-45).  Manganese works well in glass melted
> in crucibles where it was easy to maintain an oxidizing atmosphere.
> It did not work very well in tank furnaces where it was difficult to
> maintain an oxidizing atmosphere. By 1917 half of the bottles being
> produced in the United States were being made on the Owens Bottle
> Blowing Machine that was dependent on tank furnaces (Miller and
> Sullivan 2000: 166-167).  I have yet to see a solarized Owens made
> bottle.  When one finds a machine-made bottle that is solarized, it
> probably means that it was produced on a semi-automatic bottle-blowing
> machine that was hand fed from a crucible.
>
>       Early machine-made bottles are often light green in color and it
> appears that these light green bottles were on their way to being
> replaced by colorless bottles during the 1920s.  In addition to the
> light green bottles, the other dominant colors for machine-made
> bottles were amber, green, and cobalt blue.  This seems to be the
> colors that the glassmakers worked and I can not see any need to go
> beyond these basic color listings which could be in a simple check
> list form in a data base for the following colors: Colorless, pale
> green, green, amber, blue, and other.  Some products such as the Coca
> Cola bottle and the Ball canning jar had their own special color that
> does not fit into this above progression and it would be silly to
> force these bottles into the color scheme.

The area of glass color has lots of potential to tighten our dating schemes.  There are
also other markings on glass containers that can help accomplish the same thing.  I
finally tracked down the law that requires bottlers to include volume information on
labels (embossed, paper, or others) in 1913 (not enforced until late 1914).  There
should be many other small datable items like that.
>
> Summary
>
>       Already, I have suggested several things that would lengthen the
> database and perhaps discourage people from entering their data.
> However, these traits should be considered in terms of what they might
> offer in terms of information return, both in chronology and
> distribution system.  I would find it difficult to get excited about a
> system that limited itself to distribution systems.
>
> George L. Miller

A larger, more comprehensive database would be more difficult but, I feel, more
effective.  The important thing is to get group labor involved.  I suspect that many
people already have small pieces of the puzzle at their disposal.  We need to pool
our efforts.

Bill

Bill Lockhart
New Mexico State University
Alamogordo, NM
(505) 439-3732