Andrew and anyone else who may be interested:

Knowing the type of finish might also help a bit.  If it is the type of bottle I think it is, I
would guess at 1900 to mid-1920s.  If enough people with catalogs from companies
that made drug store bottles would check, we could probably pin down a fairly close
date set.  Anyone game to look?  Drug store bottles are not one of my strongest
areas, but I will check at home.

Bill Lindsey and I were discussing this a while back, but I could not find my records
on it.  So, I e-mailed Bill, and his reply is below.

I do not believe there is any solid citation available for this phenomenon yet.

Bill

---------------
Hi Bill.........

I remember the discussion thread about graduation marks on druggist
bottles, but don't remember anything else.  I looked back through my
emails (only back a couple months on this new ISP) and can find some
references, but no dating information.

I looked back through my printed emails and find only the reference to the
Gould Amendment and volume labeling....i.e. that the 1913-1914 legal
labeling requirements may have been the beginning of the graduation marks.
That also fits fairly well with what I've seen for the most part....most
graduation markings are on druggist bottles dating from the teens (like
the labeled one I have which is dated 1915, but mouth-blown).  I have not
seen any that date to the late 19th century that had graduation marks,
though there are a few other bottles that have some version of that. There
was at least one 1870's to 1880's bitters bottle that had these markings,
but they were really "dose" marks...can't remember the name off the top of
my head though.)

Also, in my looking around various bottle books with decent dating
(company) information, there are few embossed, mouth-blown prescription
druggists that post-date about 1920 and all these typically had graduation
marks.  (I do have a couple that I'm sure date no earlier than the mid
20's that are mouth-blown and have the graduation marks.)

Not sure that is what you were looking forward...will look some more and
let you know of any success.

Bill
-------------------

> Greetings, listfellows. I have exhausted my own resources in trying to
> track down information on manufacturing dates for pharmaceutical
> bottles that have embossed intervals on the side of the bottle that
> measures the volume in cc's. The specific bottle fragments I have with
> this embossing had a volume of 6 cc's, was clear glass and machine
> manufactured, and has a partial mark on the base: "/-ENS/-3/". Any
> help on this would be appreciated!
>
> Thanks in advance,
>
> Andrew R. Sewell, MS, RPA
> Principal Investigator
> Historic/Industrial Archaeology
> Hardlines Design Company
> 4608 Indianola Avenue
> Columbus, Ohio 43214
> (614)-784-8733
> fax: (614)-784-9336
> www.hardlinesdesign.com