A key concept in historic bottle dating is the high probability i. The general probability estimates noted on this website are based on a merging of reliable references with empirical observations made by this site's affiliated consulting experts see the About This Site page and the author who have been students of historic bottle dating and identification for many years. N otes on embossing, labeling, and existing research. Raised embossing and when present, paper labeling on a bottle can frequently provide important details to refine the probable manufacturing date range if information exists for the company that either manufactured the bottle i.
For example, the early mineral water bottle pictured here is known to date between based on the information provided by the embossing company name embossed on the pictured side and the glass maker - Union Glass Works - embossed on the reverse and complimentary research done by collectors Markota Researched historical information of variable depth and quality exists for thousands of different - typically embossed - bottles. Published works generally cover either a particular city, region, or category of bottles.
Quality examples of references within each of these three categories are, respectively, Gordon Pollard's book on Plattsburg, NY bottles Bottles and Business in Plattsburgh, New York: See the References page for more information. For a large majority of embossed and unembossed bottles, however, there is little or nothing formally published on the details of their origins.
Only a relative few geographic areas or areas of collecting interest have received more than cursory historical treatment and the majority of this is due to the efforts of collectors.
Time has taken its toll on records, of course, but much of what happened in the past was simply not documented well or at all as with most endeavors of common people in the past. As noted in Munsey's book, " When it comes to methods of dating bottles As Munsey also notes - " Most of what is used today to date bottles Still all true today.
This body of information will be utilized and extrapolated to make dating and typing estimates for the majority of bottles for which there is either no specific company or glass maker information available or such is not possible to determine because the bottles are unmarked i. To the authors knowledge, the first and only serious attempt at using a key to date American bottles was done in a Historical Archaeology journal article entitled A Dating Key For Post-Eighteenth Century Bottles by T. Stell Newman Newman Newman's key made a noble attempt at simplifying bottle dating, but is weakened by the fact that the subject is much too complex to be conducive to such a simple approach by itself.
Also, the format and space constraints of a journal article do not allow for the elaboration and illustrations necessary to make a key function fully Jones b. Newman wryly recognized all this with his reworking of an old saying: A pdf copy of Newman's article is available now courtesy of the SHA by clicking on this link: This website is designed to have the informational depth, pictures, and illustrations necessary to solve the problems of the Newman key though his warning still holds though hopefully less so. This entire website is essentially a key to the dating and typing of bottles.
Before jumping into the key, it must again be emphasized that no single key can get a user to an absolutely precise date for any bottle. The best the following key can do is get a user to a reliably close dating range estimate. Other information on this website usually must be reviewed to fine tune the information about a specific bottle. In addition, other references beyond the scope of this website usually must be consulted to get as complete of a dating and typing story as is possible for any given bottle.
Keep this all in mind as you progress through the key which follows and on into the other website pages Starting with Question 1 , follow through the questions as suggested. There is frequent hyper-linking between the diagnostic characteristics and terminology listed on this page and other website pages.
This is done to allow the user to get more information or clarification as they proceed through the key. Pursue these links freely since they will take a user to more details on bottle dating and identification and hopefully add to the users knowledge and understanding about the bottle being "keying out". When a dating sequence dead ends, it will be noted and other website pages suggested and hyperlinked for the user to consult.
The three questions found on this page below answer several basic questions about a given bottle. Answers to these questions will then direct a user to one of the two additional dating pages which are extensions of this key for the two major classes of bottles - mouth-blown bottles and machine-made bottles. Read the questions - and accompanying explanations and exceptions - very carefully as the correct answer is critical to moving properly through the "key.
This page guides a user through the key for seven different type and age bottles with several being side-by-side comparisons of very similar bottles of different eras. This page also shows how other portions of this website can provide information pertinent to the bottle in question.
See the About This Site page for more information about the author and contributors. For brevity, most of the specific references are not noted in the key's narratives. They are noted on the other website pages which expand on the information summarized in the key. If you know your bottle is machine-made click Machine-Made Bottles to move directly to that page. If you know your bottle is mouth-blown aka hand-made click Mouth-blown Bottles to move directly to that page. If unsure about what embossing or vertical side mold seams picture below are, click on Bottle Morphology to see this sub-page for a illustration and explanation of these and many other key bottle related physical features.
Return back to this page by closing the Bottle Morphology page. Vertical side mold seam on the neck of a beer bottle ending well below the finish, indicating that it was at least partially handmade - ca. YES - The bottle has embossing or visible vertical side mold seams somewhere on the body between the heel and the base of the finish or lip. A bottle may have mold seams but no embossing, but all embossed bottles were molded and have mold seams even if they are not readily apparent. This bottle is either free-blown , "dip" molded , or was produced in a "turn-mold" aka "paste-mold" where the side mold seam is erased during manufacturing.
A "NO" answer is much less likely than "YES" for this question as a very large majority of bottles made during the 19th century and virtually all made during the first half of the 20th century were mold blown resulting in mold seams; see the note below. A low probability though possible "NO" alternative is that the user has an unembossed, molded bottle with no visible vertical side mold seams. This can be due to one or a combination of factors including post-molding hot glass "flow" masking the mold seams, fire polishing of the bottle body, or atypically good mold fitting precision.
If necessary, look very closely at the bottle shoulder - the best location to see vertical side seams on mouth-blown and most machine-made bottles - in good light with a hand lens to see if there is at least some faint evidence of where the mold edges came together. Often the vertical side mold seams are evidenced by very faint changes in glass density in lines where one would expect mold seams to be.
One of the longest running "myths" in the world of bottle dating is that the side mold seam can be read like a thermometer to determine the age of a bottle. The concept is that the higher the side mold seam on the bottle the later it was made - at least in the era from the early to mid 19th century until the first few decades of the 20th century. Mold Seams of Bottles" chart Figure 9. Kendrick's explains in the text pages that It is true that the mold seams can be used like a thermometer to determine the approximate age of a bottle.
The closer to the top of the bottle the seams extend, the more recent was the production of the bottle. The chart accompanying this statement notes that bottles made before have a side mold seam ending on the shoulder or low on the neck, between and the seam ends just below the finish, between and the seam ends within the finish just below the finish rim top lip surface , and those made after have mold seams ending right at the top surface of the finish, i.
Although there are examples of bottles having mold seams that fit these date ranges properly, the issue of dating bottles is vastly more complicated than the simple reading of side mold seams. If it were that simple much of this website would be unnecessary! For example, the process that produces a tooled finish frequently erases traces of the side mold seam an inch or more below the base of the finish whereas the typical applied finish has the seam ending higher - right at the base of the finish Lockhart et.
The reason this is noted here is that the concept keeps popping up in the literature of bottle dating and identification ranging from Sellari's books Sellari For a broader discussion of this subject see Lockhart, et al. If unsure about what the lip , rim , or finish of a bottle is, check the Bottle Morphology sub-page. If you need more information on this diagnostic feature - including various images - click the following link: This is a "machine-made" bottle or jar and will also usually have a highly diagnostic horizontal mold seam just below the finish that circles the neck.
The picture to the left shows both of these mold seams click to enlarge. If your bottle fits this description, click Machine-made Bottles to move to the related webpage which allows the user to pursue more information on bottles produced almost totally in the 20th century by some type of automatic or semi-automatic bottle machine. The vast majority of U. If your bottle has a ground rim or lip, more information can be found at the following link: The following is a discussion of the most common exceptions to the side mold seam "rule" describing a few types of machine-made bottles on which the vertical side mold seams do not quite reach the top edge of the finish making them possible appear to be mouth-blown.
Fire Polishing - Occasionally encountered machine-made bottles may have fire polished finish rims - a process which eradicated evidence of the neck-ring mold seam on the rim of the bottle. These bottles will not have the side mold seam proceeding from the upper finish side over and onto the rim itself.
Ostensibly this was done to remove the mold seam "bump" that was sometimes left by earlier machines - an action which may have helped facilitate better sealing with crown caps, screw-thread caps, or similar closures which sealed on the rim of the finish. These bottles will, however, have the vertical side mold seam progressing all the way to the very top of the finish side, just not onto the rim. They will also have other machine-made characteristics as described on the Machine-made Bottles page.
In the experience of the website author, these machine-made bottles are rarely encountered and likely a function of early machine-made wares to s that had less precise mold fitting and resulted in the need for fire polishing to enable proper closure. Milk Bottles - Many milk bottles made with press-and-blow machines from the very early s into at least the s resulted in vertical side mold seams that gradually fade out on the neck distinctly below the base of the finish.
Click here for a picture of a typical s to s milk bottle. This exception to the side mold seam "rule" was caused by the specific workings of these machines which masked the upper portion of the side mold seam. Click on the image to the right to view both mold seam features pointed out on a press-and-blow machine manufactured milk bottle made by the Pacific Coast Glass Company San Francisco, CA. If your bottle is a milk bottle that fits this description, click Machine-made Bottles to move to the Machine-made bottles dating page for more possible dating refinement and to pursue more information.
The user is now directed to move to the last question in the Mouth-Blown bottle section of the Dating page - Question 7 - which deals with air venting marks on the bottle surface. Air venting marks can be a very useful dating tool for bottles manufactured during the late 19th century. Close inspection of both bottles shows that neither have air venting marks anywhere on the bottle. This is consistent with the flattened embossing as air vented molds allowed for the production of bottles with more distinct "sharper" embossing.
This bottle dating "key" is a relatively simple "first cut" on the dating of a bottle. Some technological changes were expensive and not adopted by glass makers. The example bottles are tracked though the Bottle Dating page questions in that If one looks closely at the thick glass in the base of the bottle, one can see that .
This all indicates that both bottles were likely produced no later than about The lack of air venting does not help with the dating refinement of bottle "A" so we actually reached the end of dating for "A" with Question 6. Subsequent research indicates that Scovill's Cincinnati office closed sometime in indicating that bottle "B" most likely dates no later than ; a reasonable an quite narrow date range would thus be the late s to [Holcombe ].
Embossed bottles like these offer some hope for the existence of additional information on the history of the product. The Blasi and Holcombe books in particular have excellent overviews on what is known of the product history and supports the date ranges determined above.
A search on the internet will turn up some scattered references to the bottle - primarily ones that are for sale or just referenced - but little historical information. The reverse side and base are not embossed. From this embossing we know that this bottle is a milk or cream bottle; so the bottle type has been already established. It is apparent that the answer to Question 1 is " YES " since this bottle has raised embossing.
The picture to the right is a close-up of the neck and finish of the Cloverdale Dairy bottle.
This bottle has side mold seams which fade out on the neck where indicated in the picture click to enlarge and do not show at any point above that on the bottle. The bottle also does not have a ground down surface at the top of the finish i. This feature would nominally yield a " NO " answer to Question 2, indicating it is a mouth-blown bottle and dating prior to about , and move one to Question 4 on the Mouth-blown Bottles section of the Dating page complex.
However, this determination would be incorrect for this bottle! It is noted in the "Exception note" just under the "NO" answer to Question 2 that machine-made milk bottles made between the early s through at least the s are the major exception to the side mold seam rule as these bottles exhibit a disappearance of the side mold seams on the neck that emulates that found on a mouth-blown bottle with a tooled finish.
However, these bottles lack other mouth-blown characteristics and have one feature that is only found on machine-made bottles made by a press-and-blow machine - a valve or ejection mark on the base. We now have a dating range - albeit a fairly wide range - for this bottle from the early s to about The user is then encouraged in the note under Question 2 to move to the Machine-made Bottles section Question 8 where one bit of additional dating refinement is that the glass has a slight straw color tint indicating manufacture after the late s.
For brevity we will skip that portion of the Dating page. Additional information on this website could be found by visiting the Bottle Bases page which would provide some information the small circular, press-and-blow machine induced valve aka ejection mark on the base picture below. The noted scuffing and wear on the bottle is a result of milk bottles typically being reused dozens or scores of times Lockhart pers. There is, however, one additional bit of information that greatly assists the dating of this bottle - the very faint rectangle embossed on the front heel of the bottle.
Pacific Coast Glass used this mark from to Roller ; Lockhart pers. Additional information is provided by the authors half pint version of this same bottle which has the "PC in a split rectangle" mark very distinctly embossed in the same location; a very common spot for milk bottles made by Pacific Coast Glass. Thus, we now can be quite certain that this milk bottle was made between and , which is consistent - though much more precise - than the date range arrived at above.
This is an example of the importance of makers marks - when such a mark is present - in the entire equation of dating a bottle. Giarde's book Glass Milk Bottles: The two latter works would provide some general information on milk bottles that would be pertinent though not specific to this Nevada example. This includes dating by glass weight Girade which indicates a pre-WWII manufacturing date for this bottle and information on plate embossing, valve marks, finishes, closures, and more Lockhart This final example will date two different age examples of bottles with virtually the same size and shape but which held different products and came from opposite ends of the country.
It is apparent that the answer to Question 1 is " YES " since both bottles have raised embossing. The embossing indicates that these have to be a molded bottles and can not be either free-blown, dip molded, or from a turn-mold. This is where the two bottles quickly diverge in the key. Bottle "A" has a side mold seam which ends immediately below the sloppy base of the finish as shown in the picture to the right upper. This yields a " NO " answer to Question 2 and we now may conclude that "A" is a mouth-blown bottle likely dating prior to The user is now directed to move to Question 4 for bottle "A" - the first question in the section of the key that deals with the dating of mouth-blown bottles.
Bottle "B" does not have a ground down surface on the top of the finish but does have a side mold seam which goes up through and to the top of the finish - see picture to right lower. It also has the highly diagnostic horizontal mold seam circling the neck just below the bottom of the finish as well as the multiple and offset seams that are indicative of a machine manufacturing. This yields a " YES " answer to Question 2 and we know that this is a machine-made bottle likely dating it no earlier than about For bottle "B", the user is now directed on the Dating page to move to the Machine-made Bottles portion of the Dating page.
To keep the dating less confusing here, we will first finish with bottle "A", then move to bottle "B" further down the page. The picture to the left top shows that bottle "A" has no evidence of any type of pontil scar or mark on the base. So the answer to Question 4 is "NO" which indicates that bottle "A" is not likely to date prior to So at this point in the Dating key we can be confident that bottle "A" dates somewhere between about and Click on the "A" picture above to see more distinctly where the side mold seams ends on this bottle.
This bottle has a side mold seam that distinctly ends right at the base of the finish. There is also an obvious and almost "sloppy" excess of glass flowing from the base of the finish onto the neck. The user is now directed to move to Question 6 , which deals with diagnostic base features. Click on the base picture for "A" to the upper left and it is obvious that this bottle has mold seams on the base. This yields a "YES" answer to Question 6 which helps confirm that this bottle was made no later than about Under the "YES" answer for Question 6 there is more dating refinement possible based on the type or orientation of mold seams on the base.
Bottle "A" has a distinctive "key mold" seam - a base mold seam that has a arch or notch in the middle portion. This yields a likely date range under this question of between and for non-pontiled bottles like "A". At this point in the dating, the overlapping date ranges from all the questions gives the user a much narrowed probable date range of to for bottle "A".
Close inspection of bottle "A" indicates no evidence of air venting marks anywhere on the bottle. This is consistent with the very flattened embossing on this bottle can not be seen in the picture. This indicates that bottle A" was produced prior to The lack of air venting does not help with the dating refinement of bottle "A" so we actually reached the end of dating with Question 6 and its conclusion that bottle "A" was highly likely to have been blown between and Bertrand which sank in the Missouri River in April had dozens of cases of these black glass Hostetter's Bitters on board.
It is likely this bottle also dates from that era, i.
Read through the introductory section of Machine-made Bottles for general information about machine-made bottles, then move on to the first question in that section - Question 8 - which deals with the glass color. This section of the Dating key is a series of independent questions where the answer to any given one is not dependent on the answer to another; a user may sequentially view each of the questions.
Since the glass does have significant sized bubbles, it likely dates during the period between and s. Move to the next question. The base picture of bottle "B" does show a diamond with "" inside on the base, but it is not the distinctive "Diamond O-I" marking shown under this question.
The latter company was in operation during the era this bottle most likely dates from - Toulouse The proximity of the company to Oregon would make it a likely source. The bottle does have a distinctive suction mark indicating that it was made by an Owens Automatic Bottle Machine. These machines were licensed by Owens Bottle Company and used by many other companies, however.
The author of this website also has a labeled only version of a Celro-Kola Company product that has a distinct Illinois Pacific Glass Company mark, i. According to Toulouse , the company also used a diamond as a makers marking, though with the company initials in it.
This is all circumstantial evidence, but it does point towards it being probable that the subject Celro-Kola was produced by IPGCo. This bottle has a cork closure finish so under this question the bottle classifies under option "A" - Cork Style Finish. This gives added evidence that the bottle definitely dates prior to or so.
Given all the information above, we can quite confidently conclude that bottle "B" dates somewhere between about and the early s. This style and size of square amber "bitters" or "tonic" bottle with a cork style finish usually dates no later than the mid s and is actually relatively uncommon as a machine-made item; most have mouth-blown features. To summarize Example 5, we have two morphologically and stylistically very similar bottles which were likely manufactured about 50 years apart. Once again more information could be found on these bottles by searching the internet. The most information can be found on Hostetter's Bitters which was one of the most popular American bitters products between the mids first introduced in [Odell ] and about , although it was made until at least as a "tonic" instead of a "bitters.
Treasure in a Cornfield - The Discovery and Excavation of the Steamboat Arabia Hawley is about another Missouri River steamship which sank in , salvaged in the s and which had at least 11 bottles of Hostetter's on board. A quick search on the internet also turned up an excellent article on Hostetter's on the Federation of Historical Bottle Collectors site at the following URL: Because of the likely regional distribution of the Celro-Kola product there would likely be less information available on it.
However, there is some which is quite useful in narrowing down the age. Fike's book notes that the product was advertised in and in Portland. This is not inconsistent with the dating done above but is on the earlier edge of the range. Ron Fowler's book "Soda: This sets the earliest date for this bottle as , further refining the probable age as somewhere between and the early to mid s.
The product Celro-Kola was also bottled earlier in a mouth-blown bottle not pictured which was produced by the Phil Blumauer Company. That companies products are also known to have been sold in label only unembossed bottles in the s click HERE for an explanation on one of the Finish Styles pages. All this points to the following conclusion - the product was in existence prior to the Celro-Kola Company being formed which explains the advertising in , but our Celro-Kola bottle can be pretty confidently dated between and the early to mid s.
This brings to an end the Dating page examples. It is not always easy to find all the information you desire on a specific bottle as is noted and outlined in the examples above. However, one can usually ascertain something more about most historic bottles if one is willing to spend some time doing additional research in libraries, on the internet, museums, and other places. This website is designed to provide a user some quick - and hopefully reliable - general dating and typing information This website created and managed by: