Machine Made Dating
There are four important characteristics for dating bottles: Mold Seams This example has embossed lettering on the body and a hand applied lip/finish. Manufacture date codes embossed on glass containers can be very useful to Soda bottle crown finish reinforcing ring date code example for Figure 2. This bottle dating "key" is a relatively simple "first cut" on the dating of a bottle. . For example, the early mineral water bottle pictured here is known to date.
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 1follow 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.
Mouth Blown Dating
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" moldedor 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.
Dating Bottles with the Side Mold Seam "Myth" 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 surfaceand 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: 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 image to the left is a close-up of the shoulder, neck and finish of a small Sheaffers ink bottle click to enlarge for more detail. The image shows the vertical side mold seam ending on the outside edge of the bead finish at a "ring" mold the upper portion of a parison or "blank" mold induced horizontal mold seam that encircles the extreme outer edge of the finish.
The side mold seam does not extend onto the top surface of the finish, i. These features are pointed out - and much more readable - on the larger hyperlinked image; click to view. The image to the right is a close-up of a small, medium green, machine-made ink bottle. As above, click on the image to view a larger and much more readable version with the various features pointed out. This termination of the side mold seam within the finish short of the rim Sheaffers ink or actually short of the finish itself green ink on these bottles makes it appear upon casual glance that these are mouth-blown bottles having either an improved tooled finish Sheaffers or an applied finish green ink.
There is also no neck ring mold seam immediately below the finish like found on most Owens machine produced bottles and on a majority of all machine-made bottles. Instead, there is one located near the base of the neck indicating that the neck ring mold portion of the parison mold produced the finish, neck, and a portion of the shoulder. This is also pointed out on the image above; click to enlarge.
The earlier green glass ink bottle is also certainly machine-made, most likely on an early semi-automatic, blow-and-blow machine based on its crudeness and lack of a suction scar. In reading through "B", there are a couple other options available to help refine the dating a bit. If one looks closely at the thick glass in the base of the bottle, one can see that the glass is not quite perfectly colorless, but instead has a slight "straw" or washed out amber tint to the glass picture of base below.
Looking at the two options under Question 8, it is clear no pun intended that this bottle matches refinement 2 which makes it highly probable that this bottle dates after and but probably no later than the s. We now have refined the bottle age range a bit more - between about and Move to Question 9 dealing with bubbles in the glass. A close look at the picture indicates no bubbles in the glass, though subtle glass details cannot be easily portrayed in a picture.
In hand, the bottle does not have any bubbles in the glass. Since the glass is without bubbles, it likely dates during or after the mids. Go to the next question. Question 10 is not pertinent to this bottle as it does not have the statement Federal Law Forbids Sale or Reuse of this Bottle embossed in the glass and it not a liquor bottle. Question 11 deals with the presence or absence of the specific bottle makers mark for the Owens-Illinois Glass Company.
Bottle Dating Examples
The picture to the left shows that the base of this bottle does have the distinctive "Diamond O-I" marking just under the "7". The "I" can appear as a dot in the middle of this mark like with this bottle, though on most it is a more or less distinctive "I". Reading down through the narrative in Question 11, we find out that the number just to the right of the Diamond-O-I mark is the last two digits of the year the bottle was manufactured, which on this bottle is a "46".
So at this point we know that this bottle was made in A user need go no further through the Dating page questions to refine the date further.
However, for example sake we will continue through the questions. For more information on Owens-Illinois marks, see Bill Lockhart and Russ Hoenig's a retired senior engineer for Owens-Illinois recent work - available only on this website - at the following link pdf file: Question 12 deals primarily with cork versus screw top closures.
This bottle has neither of the closure types noted; it instead has a crown top. As the information under this question notes, ACL's in the U.
By considering the dating information arrived at above - excluding the makers markings on the base - we can still make a reasonable determination that this bottle almost certainly dates no earlier than ACL, lack of bubbles and could be as recent as the s straw tinted colorless glass. The makers mark cinches the date in the s of course, but without this marking the bottle date could not be refined further. This site contains very limited information on specific companies that utilized bottles; such information is impossibly beyond the scope of this or any site or book.
However, if more information were desired a quick search on the internet using the words "Mission Dry Corporation" the embossing on the base would lead a user to an assortment of information indicating that the company was bottling as early asthat its primary product was soda water, that these style Mission bottles date into the mids, and miscellaneous information about specific company products like cans, labels, etc. One of the top returns on the search list would be the "e-Book" entitled Bottles on the Border: This e-Book is now posted on this website and contains an extensive amount of information on soda bottles in general as well as specifically to those used in West Texas.
Click Historic Bottle Related Links page to find links to the assortment of pdf files that comprise this printable e-Book.
Click on the bottle photos to view a larger version of the image. There are no sharp lines to the bottle, just rounded corners and features. This question asks if there is either any embossing on the bottle or if there are mold seams present on the body, shoulder, or neck. A thorough search of the bottle glass surface finds no embossing and no apparent mold seams anywhere.
The answer to Question 1 is "NO", indicating that this bottle is either free-blown, dip molded, or from a turn-mold. The user is now directed to move to Question 3 which differentiates unembossed, seam-free bottles into several categories.
Since this bottle is not cylindrical the answer to Question 3 is "NO". We now know that this bottle was either a free-blown or dip molded and that it is highly likely to date prior to - possibly much earlier. As the picture below right shows, this bottle does have a blowpipe or "open" pontil scar on the base. See the pontil scars page for more information. The blowpipe style pontil scar puts the date of this bottle as no later than approximately and does indicate that it could date back to or even before.
The overall crudity of the bottle would indicate a manufacturing time on the earlier end of this range. Thus, our Dating key derived age range for this bottle is towith a high likelihood of dating prior to This bottle keyed out much quicker than the first example because this is as far as the dating key goes for free-blown bottles.
This early American-made bottle was free-blown not dip molded most likely at a New England glasshouse between and References that could be consulted for this information include: This example will date two slightly different examples of the same patent or proprietary medicine Hall's Balsam for the Lungs to illustrate how the Dating page questions can differentiate the age of different versions of the same type bottle made for a lengthy period. The embossing on both bottles is relatively flattened and not particularly "sharp.
It is apparent that the answer to Question 1 is "YES" since both of these bottles have embossed lettering which indicates they are molded bottles; they can not be either free-blown, dip molded, or from a turn-mold. The picture to the right is a close-up of both bottle finishes. It shows that the side mold seam on both bottles stop well below the top of the finish.
On close observation it is apparent that neither bottle has a ground down top surface to the finish.
This yields a "NO" answer to Question 2 and we now may conclude that these are both mouth-blown bottles almost certainly dating prior to The user is now directed to move to Question 4 - the first question in the section of the key that deals with the dating of mouth-blown bottles.
This question deals with whether the base of a bottle has a pontil scar, and if present, what type of pontil scar.
The pictures below show that neither of these bottles have any evidence of a pontil scar on the base. So the answer to Question 4 is "NO" which yields an earliest manufacturing date for both bottles of about At this point in the Dating key we can be confident that both bottles date somewhere between about and The user is now directed to move to Question 5which deals with way the bottle was finished, i.
Click on the picture above to see more distinctly where the side mold seams end on the two bottles. This is the point in the Dating key where our two bottles diverge from each other. Bottle "A" has a side mold seam that distinctly ends right at the base of the finish. There is also a "drip" of excess glass on the left side of the neck that appears to have flowed from the base of the finish onto the upper portion of the neck.
Given these two diagnostic features, the answer to Question 5 for bottle "A" is option A - this bottle has a "true" applied finish which very likely dates "A" as no later than to We now have narrowed bottle "A" down to a high probability date range between and Bottle "B" differs from "A" in that the side mold seam ends a quarter inch below the lower edge of the finish and there are horizontal, concentric tooling rings around the upper neck and finish "wiping" out the mold seam.
If one looks closely at the middle portion of the neck on bottle "B", there is a slight bulging out towards the outside of the bottle of the inside glass surface. This is a common feature resulting from the action of the "lipping" or "finishing" tool. This bottle clearly has a tooled finish which makes option B the correct choice for bottle "B" under Question 5. This feature makes it likely that this bottle dates from or after the late s. We now have narrowed bottle "B" down to a highly probable date range of the late s to The user is now directed under all of the Question 5 options to move to Question 6which deals with diagnostic base features.
This question asks if there are any mold seams within the outside edges of the bottle base. Click on each of the bottle base pictures to the left and it is apparent that both bottle "A" and "B" have mold seams on the base. This yields a "YES" answer to Question 6 for both bottles and suggests a date of about to as the latest date that these bottles would likely have been manufactured.
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, as follows: This yields a likely date range under this question of between and the mids for non-pontiled bottles like "A".
At this point in the dating, the overlapping date ranges from all the questions gives the user a narrowed probable date range of to the mids for bottle "A".
At this point non-pontiled base, post-bottom mold conformation, tooled finish we now have a probable date range of between the late s and for bottle "B". 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 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 aboutand 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.