M inside a circle: Maryland Glass Corporation

Maryland Glass Corporation

Baltimore, Maryland   


“M inside a circle” marking 

This mark was first used in 1921, according to trademark information reported in Arthur G. Peterson’s  400 Trademarks on Glass  (1968).  However, Julian Toulouse, in Bottle Makers and their Marks (1971, page 341) writes that the “M in a circle” first appeared on bottles in 1916.  I think his information is incorrect and the year 1921 did see the beginning of the use of this mark.

Maryland Glass Corporation was organized in 1907 as a vehicle for making large quantities of Bromo-Seltzer bottles for parent Emerson Drug Company, of Baltimore.   Emerson Drug Company (founder and president, Issac E. Emerson) had been incorporated in 1891, and because of increasing sales needed a reliable source of supply for the large quantities of glass bottles needed.

This company was soon specializing in producing all kinds of cobalt blue bottles and jars.  Many of the blue glass containers made for Phillips Milk of Magnesia, Bromo-Seltzer,  Bromo-Caffeine,  Vicks Vapo-Rub,  Noxzema, and other products were produced here.   Maryland also produced clear glass as well as cobalt.

The “M in a circle” mark is seen on tremendous numbers of glass containers from the 1920s through the 1960s, and cobalt blue jars and bottles from trash dumps of this time period are often found that bear this mark.  Many of these containers have no identification or brand markings other than the “M in a circle” on the base.

Maryland produced the most commonly-seen type of figural “violin bottle” or “fiddle bottle”  in various shades of blue (and probably other colors) although these bottles were not usually marked.  They may bear a mold number on the bottom.

3 Maryland Glass Corporation bottles in cobalt

Maryland Glass Corporation bottles: (Left to right) marked “Phillips Milk of Magnesia Tablets” with an “M”; Bromo-Seltzer Emerson Drug Co. bottle with “M in a circle / 24” on base; plain blue medicine/chemical bottle with “M in a circle / 7” on base.

Maryland Glass was acquired by the Dorsey Corporation in 1968, and I believe that the “M” mark was used for a time thereafter, but eventually discontinued sometime in the  1970s.

According to info supplied by Ernie Dimler (see his posts in the Comments section of this page for more background info), the last glass bottles made by Maryland Glass were produced in 1980.

M in a circle bottle base

“M in a circle / 7” Base of plain bottle pictured on right in group photo.

Bromo Seltzer bottle base

Bromo Seltzer bottle base

Phillips Milk of Magnesia Tablets bottle base

Phillips Milk of Magnesia Tablets bottle base, with “M” for Maryland Glass.


Maryland also used the “plain M” on some bottles, and rarely, an “M inside a G”, which are listed on the Glass Bottle Marks, page 4.

NOTE: An “M in a circle” logo is also seen on the base of tableware, novelty glass shoes, upscale reproduction pattern glass, various colored glass toothpick holders, etc, and in those cases it is the mark of an unrelated firm, the Mosser Glass Company of Cambridge, Ohio.  (Maryland Glass made, for the most part, utilitarian and commercial containers.) 


Click here to go to the Glass Bottle Marks (page 4).

Click here to go to my Home Page.

55 Responses to M inside a circle: Maryland Glass Corporation

  1. Ernie Dimler,curator,conservator. says:

    You are correct, partially, Heuisler family ran Maryland Glass, Isaac E Emerson was the chairman Executive committee, Philip I Heuisler, president, Joseph F Hindes, Vice President and Treasurer, Parker Cook, Secretary, Harry J Williams is Manager. This is what is listed in a Maryland Glass Corp Invoice dated November 26 1913, Home Offices listed at Bromo Seltzer Tower Building with Mt Winans listed as the Works. Maryland Glass was a collaboration between Issac E Emerson and Philip I Heuisler, specifically for making bromo seltzer bottles in the beginning, later making cobalt for many other companies like Sharp and Dohme as early as the 1920s, Evening in Paris, Milk of Magnesia, Noxzema, Vick’s, along with flasks produced in the 1970’s.

  2. Ernie Dimler says:

    I have the Maryland Glass bankruptcy papers here in our collection. According to employees the last glass bottles were made in 1980,The lawsuit continued till the 80s when bankruptcy was final Some employees had individual suits for Insurance Claims for medical bills never paid, It was ugly at the end when employees would race to the bank ,worried about not enough money in bank for all checks. I am meeting Ann Heuisler tomorrow there is no telling what I will learn.Ernie

  3. Ernest Dimler says:

    If the bottle is cobalt blue it is likely something from evening in Paris perfume,or possibly nail polish remover from the 1950’s to 60’s. Send pic to site please.

    • Ernie Dimler says:

      Hi David, just spoke to Louis Demely who worked at MD glass for 24 years and was friends with Phillip Heuisler the 3rd super at the plant, Maryland glass history at the end/The first buy out was by the Warner Lambert co in 1956. After this buyout the plant changed for the worse according to Demely, Chattanooga glass purchased Maryland Glass Co from Lambert Pharmaceutical; Chattanooga glass sold to Dorsey trailer Co in 1979. I have the anniversary bottle in our collection from Chattanooga from 1978 when it was made. Dorsey took over in 1979 and the last glass bottles were produced in 1980 according to Bill Burke 40 yrs,MD glass, Louis Demely 24 years, and countless others who are listed along with their job they did— Mold maker , Drafting etc. The Owens machines came in 1914 according to paperwork I have from 1914 receipt. Machine was bought from Hazel Atlas, M in a circle was started in 1921 when the transition from cork to lugs took place, the corkers with M in circle are some of the last corkers made, I have only seen 1. It is in our collection at the Bromo Seltzer Tower along with over 500 items Bromo, Emerson related. We now have about 500 Maryland glass pieces in our collection, also Receipts, bottles, ephemera etc. Hope this helps nail down how the ending of Maryland glass came about. Ernie Dimler, Curator Bromo Seltzer Tower Museum and Maryland Glass expert. We are visiting with Ann Heuisler on Fri – I will keep you informed about my research.

  4. Lalinda says:

    Hi! This is great information! I can’t say I know anything about glass, but I found a bottle while hiking that was interesting looking enough for me to bring home and clean off. I don’t think it is too old, or maybe it is not really old at all, but still an intriguing piece to me. It is a clear bottle that measures just shy of 4 inches in height. There is an “M” in a circle on the bottle with the number “2” below it. All sides are patterned – kinda lighting bolts and sun rays in an art deco type of style. The number “62” is on the neck. I appreciate any help or information!

    • David says:

      Lalinda, I don’t know about the bottle, but will approve your post for publication. Perhaps someone might run across this comment and know more about it. You could also email me a pic (my email address is at the bottom right-hand corner of any page on this site).

  5. Jim coyle says:

    Excellent! Looking forward to working with you.

  6. Ernest Dimler says:

    UDELE,Your bottle is a common Medicine bottle with measurements,This could be anything from citronella oil to cod liver oil,Henry K Wampole also used these for Cod Liver Oil,These also have the M in a circle on the bottom.

  7. Ernest Dimler says:

    How did you like our Maryland Glass and Bromo Seltzer collection Jim Coyle ?

  8. Udele says:

    I have a clear glass bottle. M in a circle and a 7 on the bottom. There is an odd 3iii on the front wider flat side. It is skinny 5in tall. 2″x1″ Rectangular jar. Rounded corners in the back with front two corners “sliced off” to make 3 flat sides on the front of the bottle. It would have had a cork. No screw top markings. Any idea what it could have been used for at one time?

    • David says:

      Hi Udele,
      You have a “generic, all-purpose” pharmaceutical/druggist bottle. For more info on the “weird 3” symbol, check out my reply in the “Comments” section of this webpage: http://www.glassbottlemarks.com/bottlemarks-4/. Please scroll down to my post (replying to Karen, written on July 27, 2013). Many readers ask about this “odd 3” marking which appears on many older druggist bottles. They were made by many glass bottle manufacturers, yours being a product of Maryland Glass Corporation.
      Hope this helps!

    • Elizabeth says:

      I was born and raised directly across the street from The Maryland Glass Corp. The Heisler Family owned that company. My parents started a lunch room type of business and it grew into the neighborhood Pub of Mount Winans. Our family business which lasted over four decades became a meeting place for glass factory workers and neighbors. I later worked there in the office I have many blue glass bottles including the famous Bromo Seltzer ones and the fiddle ones. I own two complete sets of the BiCentenial Bottles. Each bottle shows a scene from the Revolutionary War.

  9. Jim Coyle says:

    Yes, Sorry.


  10. Jim coyle says:

    I am coming to visit this Saturday.


    • David says:

      Jim, I am assuming your message is intended for Ernie, referring to the Maryland Glass room in the Bromo Seltzer Arts Tower.

  11. Ernie Dimler says:

    I am Curator of the Bromo Seltzer Building Collection, We have over 100 Maryland Glass Cobalt Blue pieces at the Bromo Seltzer Arts Tower ,We are now working on our Maryland Glass room.with over 500 Maryland glass pieces,including Maryland Glass Documents,Paperwork and over 100 cobalt blue pieces all from Maryland glass ,including Piggy,owl,bear,sea horse,fiddle bottles ,cigarette holders,flasks,noxema,bromo,milk of magnesia,sharp and dohme,poison bottles, just to name a few,The M in a circle was first used in 1921 when the first lugged bottles were used according to calender’s with pics of lugged bottles.that are dated.Here at the Tower.The piggy was made in 1950 to 1951 according to Bill Burke who worked there for forty years.Who is my go to expert,My father also worked at the Bromo Tower for 12 years from 1955 to 1967.

  12. Jim Coyle says:

    Thanks for clarification.

  13. Jim coyle says:

    Looks like David has given you what you needed. There was a period in the early 1900’s when the MD Blue Glass did not have the “M” on them. So it makes it difficult to clearly identify every cobalt blue glass item as MD Glass. I have been researching to see if someone wrote a catalogue on all the MD Glas products; unfortunately I have not found this.

    My father worked there from 1929 to 1969; his entire career.


  14. Joseph Haley says:

    My son just gifted me a cobalt blue MG Co. bottle. I understand the circle M mark, but I have questions about the other marks. Over the ‘M’ the letter ‘L’. Under the ‘M’ is ‘Design PA’ (the D looks more like an ‘O’,but that doesn’t seem to fit, and I can not find a Design PA on the map so far. Under this mark are the numbers ‘97178’, and under that the number ‘5’. I assume the 5 is a mold mark.
    Joseph Haley
    Tallahassee FL

    • David says:

      Hi Joseph,
      Not sure about the “L”. but the other markings mean “DESIGN PATENTED” (by the United States Patent and Trademark Office) and the patent number of that particular bottle design which is D97178. I searched the “Google Patents” site and found this: (The bottle design was patented in 1935). https://patents.google.com/patent/USD97178S/en. Hope this helps!

  15. Glen Mullins says:

    I have pictures of some products,I have of Md.Glass, cobalt blue,if anyone is interested I can be reached at. glenfromberlin1934@hotmail.com

    • Jim coyle says:

      Thanks for your note. Glad you have an interest in the Md. Glass Corp materials. I have collected most of the various bottles they made; my focus is on the specialty items they made which were given as gifts to customers and friends.

      Jim coyle

  16. Diane says:

    does anyone know of a site i can go on that I can look up pieces? I have a set of ruby footed cut glasses and I’m trying to find out the name of them. I took a book out of the library titled “GLASS OF CUMBERLAND MARYLAND AREA” by Dale Murschell. They were in there, thats how I know they are by Maryland Glass, but there wasn’t any style name. Please email me at Dianevgi@aol.com if you know where I can find these. I usually don’t go on the internet so much, so I probably won’t go on this site again, so an email would be great. Thank you for any help you can give me.

    • David says:

      Hi Diane, I am posting your query here. Perhaps a reader will contact you with more information. I tried to find Dale L. Murschell’s current contact information online without success. There is someone by that name who lives in West Virginia but it may not be the same person.
      I am sure the ruby footed glasses you refer to were not made by Maryland Glass Corporation. I do not have a copy of Murschell’s book; however, from my understanding, his book concentrates on glass factories located in the Cumberland, Maryland area (Allegany County). Maryland Glass Corporation (subject of this webpage) was located in Baltimore (Baltimore County). The Maryland Glass Company of Cumberland, Maryland was unrelated to Maryland Glass Corporation of Baltimore. Maryland Glass Corporation made primarily (not exclusively) container glass. Maryland Glass COMPANY of Cumberland apparently made tableware, not bottles.
      Best regards,

      • Diane says:

        David…thank you….I guess I will have to go back to the library and check other books for these glasses 🙂

        • David says:

          Hi Diane, just to make sure I’m making myself clear………….if those exact glasses ARE illustrated in Dale Murschell’s book on the glass of Cumberland, Maryland, then I would suggest you just need to contact Mr. Murschell and see if he has any more info about the pattern name, values, etc. (As far as I know he is still alive, but I don’t know that for sure.) I strongly doubt you will find the glasses shown in any other books. Would you be able to email me a pic of the glasses? Please send to my email address which is listed at the bottom right-hand corner of any page on this website.
          Best regards, David

  17. Jim Coyle says:

    Thanks for the technical info about 1921. That helps with identifying pieces after that.

  18. Jim coyle says:

    My father got a chemistry degree from Loyola College in 1929. He went to work at MD. Glass as a chemist. A fellow Loyola classmate was the son of the Corp. President, Phil Heisler. he worked there til his death in 1969, rising to the position of Superintendent of Glassmaking.

    the M on the products came about around 1930. But not all products had the symbol on them. many of their gift items were unique and not produced in large quantities. I think there most famous gift was the blue glass violin bud vase. I have been attempting to collect these gift items over the years. at the Bottle Club exhibition this past Spring, I found an item I was not aware of made in the early 1930’s. It is a blue glass ashtray with the Md Glass name and M on the bottom and identified as a Christmas gift. It looks like a flat tea bag holder with a Ladle handle. It was dated 1934.

    I have been searching for the blue glass piggy banks that they produced in the late 1940’s into the 50’s. Since they did not have an escape hatch, they likely were broken to retrieve the coins.

    I wish that someone had catalogued all of their products from the beginning of the seltzer bottles.


    • David says:

      Jim, the cobalt blue glass piggy banks sound beautiful and adorable, and I would guess that occasionally one of them shows up on ebay! I’m sure a few people kept them as keepsakes, or for decoration and didn’t store coins in them, and so never felt the need to break them! At least I certainly hope so!!! Also, I’m not trying to pick an argument with you, but according to Arthur G. Peterson’s reference book “400 Trademarks on Glass” (1968) the “M inside a circle” was used beginning in 1921. His information came from researching the actual United States Patent & Trademark Office records, so I assume it is correct (or at least, that is assumedly the information that was supplied to the government office by Maryland Glass Company when applying to have their trademark officially registered).
      Best regards,

  19. Jack Burkert says:

    Hello to all you “posters” – I sent this to Jim initially, but realized many of you may have stories to tell or things to share. I work for the Baltimore Museum of Industry. I am unofficial in asking, but could you relate the “story” of Maryland Glass for me sometime? I would love to take notes. Do you have an “artifacts”? Many thanks, Jack Burkert – burkert.jack@gmail.com

  20. Jim Coyle says:

    That is great! Maybe someone could start a MD. Glass Corp. Alumni group. It could be a subset of the Baltimore Bottle Club.

    I am surprised by how little has been researched and written about the MD. Glass Corp since it was a major company in Baltimore for 70 years. For example, I can’t find a written catalog of all the products and gifts they made all those years. My knowledge is from my memory as a son of a 40 year employee.


    • Jack Burkert says:

      Jim, I work for the Baltimore Museum of Industry. I am unofficial in asking, but could you relate the “story” of Maryland Glass for me sometime? I would love to take notes. Do you have an “artifacts”? Many thanks, Jack Burkert – burkert.jack@gmail.com

  21. Wanda Knickman Barthel says:

    My Pappy, Charles Knickman, his sons, my father Maynard Knickman, and my uncle Sonny Knickman worked at Maryland Glass all their lives. I still have some pieces my Dad brought home. A colbalt blue top hat, a ringed vase and a violin. At my childhood home in Elkridge we had one of the machines Pappy made. I don’t know what happened to it. I do have a copy of the blue prints. I believe Pappy was a glassblower in his early years.

  22. Jim coyle says:

    My father, Thomas Coyle, worked there for over 40 years, ending as Superintendent of glassmaking. Do you know where any others of the cigarette jars may be available for purchase? secondly, did anyone ever catalogue all the various bottles and jars that the company made over the years?
    I wish there were a more documented history of the MD Glass Co.


  23. Glen Mullins says:

    I worked for me. Glass corp for22 yrs.i had the cigarette holder you speak of,in addition to the fish and crabs it also has Maryland my Maryland on it. On the bottom it has Christmas 1932. I was a mold maker there, my son now has the cigarette, humidor,. My name is Glen Mullins

  24. Randall hughes says:

    I am inquiring to see if anyone knows what the #s under the M trademark stumble stand for?

    • David says:

      Randall, usually, the single or double-digit numbers along with the “M in a circle” trademark are mold numbers— identifying the mold which was used to make the item.

  25. jim Coyle says:

    Among the specialty bottles they made was a very unique cigarette holder; it was a blue jar, similar in size to a Noxema jar, with a fish, crab and lobster embedded in the glass. It also had a divider with a silver top to hold the cigarettes. If anyone has seen such an item, I would be pleased to know.

    • Ken Huffman says:

      My grandpa worked at Maryland Glass for 50 years, also his sons and daughters were lifelong employees. When I was a child, I helped Pappy build machines in the extra bedroom which he gave to to company and significantly increased quality and production. My grandfathers name was Charles Henry Knickmen. TY. Ken Huffman 540-718-8111

      • David says:

        Hi Ken, and thank you for the information! I’m posting this on the page, so perhaps others with a family history relating to Maryland Glass could contact you. ~David

    • Glen Mullins says:

      Jim my name is Glen Mullins. I was a mold maker at md.glass corp. for 22 yrs,I had the cigarette humidor you speak of.my son has it now.i could probably send you a picture of it.

      • David says:

        Please let me chime in as well………..if you see any info here on my site that you believe is in error, please feel free to contact me. I would like to have my webpage on Maryland Glass (as well as my pages on other glass companies and topics) as accurate as possible. I realize there is ALOT that is not known, or at least is not published, about glass and glass companies, so bottle researchers just go by the best info available. Take care and thanks for your input.

      • Jim Coyle says:

        That would be great for my records. Thanks.

    • Ernie Dimler says:

      We have one at the Bromo Seltzer Arts Tower Museum room.on the 15th floor along with 15 floors of great art and artist studios.We have 2 in our collection.These are real hard to find items.

Comments/Replies: All comments are moderated so will not be published immediately. Because of mail volume received, and time and energy restraints, some questions may not be answered individually, especially if the subject is already addressed elsewhere on this site. This website is not intended as an appraisal service, but as a resource for background info on glass companies and the marks they used, so I usually delete "What is this bottle worth?" types of queries. Thank you very much for your patience & understanding !!