America's First Microscope and Telescope Maker, Susanna Davis Sommer

Move over Charles A. Spencer, and Amasa Holcomb, Susanna Davis Sommer is America's first Microscope and Telescope Maker. 

You probably haven't heard of Susanna Davis Sommer, let alone that she was the first American microscope and telescope maker. She was a celebrated Dutch professional having practiced since the 1720s in the Netherlands, arrived in America in 1749, and advertised in the New York Gazette in 1751 and 1753 that she was a grinder of all sorts of glass lenses, producer of spectacles, four draw telescopes and microscopes. She achieve recognition in her own life time, with her scopes having been in the collections of common people and the nobility. Both the French and the English acknowledge her achievements too. Yet, we in America do not learn about her technological contributions from school classrooms, museums, or historical sites. That she developed a table top dissecting microscope and her own version of a projecting microscope, the first of which would be copied by later scope makers. She also happened to be a widowed at a young age and raised three children on her own. Later her grandson, Ananias Cooper would become a notable Philadelphian merchant and goes on to fight along side Washington at Valley Forge. At the time of her arrival in 1749, she was the only glass grinder in New York, making her the only source for domestically produced scopes available for field research during the enlightenment and for telescopes or spy scopes during the French and Indian war. She helped us into the enlightenment by providing what the French and English considered the highest quality lenses for science in the western world.

"A brass telescope with four draw tubes, made by "Juffrouw [ Widow] Sommert" was in the Amsterdam Aron de Pinto collection, together with a microscope by her hand." - From Earth-Bound to Satellite: Telescope, Skills and Networks, by BRILL. 

Last summer, I represented her in typical Dutch-American garb while demonstrating how to grind glass to tourist and children at Fort Erie on Lake Ontario. By the time I am done with the demonstration kids know the difference between convex and concave lenses, the name Susanna, and learn that physics is not all that scary. The best part was, they loved it! Sommer is someone I care a lot about and hope that you all will spread the word, that one hell of a lady was the first crafter of telescopes and microscopes in America !


Early Life: 

Susanna Davis Sommer's early life is not well known. There is some speculation by her decedents in the US that she was born in 1695 in Wisbeche, Cambridgeshire, England and prior to marriage went to the Netherlands. A survey of the babies born in this parish turns up one "Susanah Palmer" born in 1695; unfortunately, the surnames of Palmer and Davis do not line up and the birth year was likely inferred form the Palmer date.

I believe it is more likely that her parents and heritage are likely either German or Dutch. Possibly, being born on the continent with the English birth place being mistaken, or with the possibly of having moved to England with her parents as refugees and then moving to the Netherlands. This particular English parish had a number of protestant refugees settling in the region in 1695 opening the door to her being the child of people seeking religious freedom. Another clue to her heritage is that late in life she and her daughter Elizabeth later joined the German speaking Moravian Church, becoming one of the original founders of the Fulton St. Church in Manhattan and is possibly the reason for her coming to America. I do find it surprising she would leave a thriving business, but this may have also been a way for her to semi-retire from her notoriety.

A Partnership: 

Records for Susanna's life picks up around the time of her marriage. In 1727, her husband Balthasar took out an advertisement in a Dutch paper.

Optic Glasses.—Notice is hereby given, that Balthaser Sommer, could be contacted in Amsterdam, both at the coffee shop of J. van der Wal at the “Paradijsvogel”, Bird of Paradise, on the Rokin, or in The Haue, Grinds all sorts of Optic Glasses to the greatest Perfection, such as Microscope Glasses, Spying Glasses of all Lengths, Spectacles, Reading-Glasses, for near-sighted People or others; Also, Spying-Glasses of three Feet long; which are to set on a common Walking-Cane, and yet be carried as a Pocket-Book; all at the most reasonable Rates.” - November 10, 1727

Just two months later, we see a possible reason for Balthasar looking to drum up new customers. The baptism of what is probably their first child, Lea Susanna Sommer. Balthasar and Susanna will have two other daughters; Mary and Elizabeth Sommer who will later follow her to America.

De Nederlandsche leeuw, Maandblad van het Koninklijk Nederlandsch Genootschap voor Geslacht- en Wapenkunde, MAANDBLAD van het Genealogisch-heraldiek Genootschap „De Nederlandsche Leeuw." page 231, under the surname of "Sommer".

Van dezen naam is 19 Jan. 1728 in de Evangelisch Luthersche kerk te 's-Gravenhage gedoopt Lea Susanna, dochter van Balthasar Sommer en van Susanna Davis.  

Of this name is 19 Jan. 1728 in the Evangelical Lutheran church in The Hague baptized Lea Susanna, daughter of Balthasar Sommer and Susanna Davis.

While speculative, the three daughters would have likely helped their mother in the "studio". Later before moving to America, Susanna choose a buyer for her studio. The buyer was Nicolaas van Leewen who's apprentices were his own two daughters - Anna and "Sanderina" - who a few years later over his shop and place their first advertisement on May 10, 1757 as grinders of glass and producers of magnifying products. Like father like daughter / like mother like daughter... melts one's heart ! 

Unfortunately, Balthasar will pass in 1733 but not before having made a name for himself. It is likely that Balthasar was trained in Bavaria or in the Netherlands to be a glass grinder. He was quick to pick up on trends. A glass grinder can make a living making spectacles as seen below, however, Balthasar is known to have made handheld screw microscopes that could be used to explore the world around oneself. 

Marian Fournier produced a catalog following the history of the microscope. For instance, the screw microscope was invented in 1694 by the Dutch mathematician Nicolaas Hartsoeker, later James Wilson will make his version of the screw microscope in 1702. Edmund Culpepper was first apprenticed as an engraver and later in 1720 produced a print in exact duplicate of the screw microscope he had available. Unfortunately, we do not know when our Balthasar Sommer was born, but know he died in 1733. While it is possible he died at a young age, it is more likely he was both older and a contemporary of Edmund Culpepper. Balthasar too made a screw microscope according to Fournier. See "Early Microscopes, A descriptive Catalogue" Leiden: Museum Boerhaave, 2003.

In another book we find the following, "For instance, in that of the merchant Anthony Bierens (auctioned in 1747), some 30 optical objects were present, including “an object and an eye glass fitted in a wooden holder, for an astronomical telescope of B. Sommer”.136". See "From Earth-Bound to Satellite: Telescopes, Skills and Networks", edited by Alison D. Morrison-Low. The book notes that auctioneers used, "The famous Sommers", as they were considered a team, to promote the products of the various auctions.

By Her Own Hand:

Susanna Davis Sommer will produce microscopes and telescopes by herself for roughly 32 years, with half of those years being in America. 

With permission, a projection microscope made by Susanna Sommer in the collection of the Museum Boerhaave. This museum has one of the largest collections of microscopes in the world, with many interactive projects for children. The microscope below has a tube that is connected to the large square plate. The plate opens like a book. Inside is a mirror on one side and the input lens to the tube on the other. The mirror reflects light from the sun onto the specimens plate and through the tube to a wall. Very similar to the overhead projectors used in schools from the 1980s and 1990s.

Her ingenuity was recognized by the English:

The book: “The microscope made easy or Describe the best and newest microscopes and any treatment. As a compliment of the amazing discoveries made with the magnifying glasses.” - by Henry Baker, 1744 

Page 8 - The solar microscope of Lord [Heere] Wilson (This system)… is sufficiently similar to that of the Lord Sommers, for what many years have been in use among our Dutch comrades, and now at the widow's own [hand], living in Amsterdam on the Reguliers gragt at Kerkstraat, is being sold.”

Page 10 - [For the Wilson's screw microscope]... “”M" is a flat strip of ivory, called a shackle [specimens’ holder], with four round holes there, in which the objects are placed between two Muscovich [glass] slides, showing the same d, d, d, d [on diagram]...

*Instead of Muscovich glass, the objects in the above-mentioned System of Sommer, Placed between two separate skeins of French or England glass thereto, which for some comrades will be preferred.” 

Did you catch that ? Wilson's are similar enough (a.k.a "good enough") to the long standing Sommer's scope, to be used by researchers. This comparison is like saying that while I love and own a VW coup... its still not a porch. More interestedly, why weren't the French or English using their own glass if it was of a better quality? Unfortunately, I am not sure of the difference between using two "slides" vs. two "skeins" but it seems to have improved the quality, and the author complains that systems that do not use the skein style have a difficult time with their specimens moving (floating) impeding observations. 

After this publication we find two advertisements likely capitalizing on her recent publicity.  In 1744 the adds read, "Optic Glasses.—Notice is hereby given, that Widow of Balthaser Sommer, could be contacted in her shop on the Reguliersgracht in Amsterdam...". Another add is taken out the year before she leaves for American in 1748, with her studio being sold to van Leewan, and Sommer arriving in America in 1749. 

In America:

Traditionally, New York has required immigrants to live in the colony for one year prior to applying for Freeman status, which allows a person whether merchant, tailor or candle stick maker to sell and carry on business. It was also a bit of a status position, as gentlemen also registered despite not having an occupation. There was not a stigma for a gentlemen of means to choose to join a group made up of primary people with jobs. The Freeman status was given to people who applied for it and paid a fee, and was in keeping with the Burger roll that had preceded it. Interestedly, those people with prior Burgher status could pass this onto their sons and son-in-laws and it continued right into the 19th century in New York. The Burgher rolls of New York included people of Dutch, German, English and other ethnicities, plus a number of women. Unfortunately, the Freeman rolls are not complete, and I could not find our Susanna Davis Summer. 

New York City's population in 1750 was about 12,000 people, and while not the largest port, it was the largest warehousing facility in the colonial era. The "Vitals" of New York has one "Elizabeth Somers as resident in 1751. Elizabeth Somers is her daughter, likely the youngest. Later, Elizabeth "Sommers" (1729-1785) born at Gravenhaag marries Reverend Andrew Langaard in 1763 a pastor in the Moravian church in Pennsylvania. In 1752, her daughter Maria Elizabeth Sommer is also listed as "Resident". Maria or Mary marries while still back in the Netherlands to the merchant Cornelius van "Kuyper". Right after their arrival in 1753, their child Ananias "Cooper" was born on August 31st, 1753 and baptized on September 3rd, 1753 in the Moravian church on Fulton St. in Manhattan. Later Ananias will marry Bridget Burke in Philadelphia. His advertisement is below:

Brush Manufactory.—Hogs Bristles....The Subscribers having erected a Brush Manufactory at No. 4, Peck's-slip, where they propose carrying on the brush making business in all its branches, Store-keepers and others may be furnished with all sorts on as low terms as any imported, to which they hope the preference will be given them, as the work is equally good if not better; and as they will warrant their work not to fail till worn out by use, they flatter themselves with expectation of getting a sufficient supply of this country bristles, that they may not be under the necessity of importing their stock from England; the farmers, by being careful in the season of killing, may have sufficient to supply them in this business. Country store-keepers would be the most proper persons to collect them. Ananias Cooper and Company.—New-York Daily Advertiser, December 26, 1787.

Susanna Sommer's first advertisement in the NewYork Gazette or Weekly Post Boy was in 1751 and the second in 1753 to notify everyone that she had moved to a new location.

1751 - “Widow of Balthaier Sommer Grinds All Sorts of Optick Glasses.
Notice is hereby given to all persons, that the widow of Balthaier SOMMER, late from Amsterdam, now living in “Beekman-Street, New York, next door to Mr. Lodowick BAMPERS [ No. 24 Beekman St. ], grinds all sorts of optics glasses to the greatest perfection, such as microscope glasses, spying glasses of all lengths, spectacles, reading glasses, for near sighted people or others. Also spying glasses of three feet long, which are to be set on a common walking cane, and yet be carried in a pocket book, all at the most reasonable rates. -The New-York Gazette or the Weekly Post-Boy, October 18th, 1751.

1753 - Optic Glasses.—Notice is hereby given, that the Widow of Balthaser Sommer, late from Amsterdam, now lives next Door to Mr. Laffert's on Pot-Baker's Hill, in Smith-Street [ William St. ], New-York, Grinds all sorts of Optic Glasses to the greatest Perfection, such as Microscope Glasses, Spying Glasses of all Lengths, Spectacles, Reading-Glasses, for near-sighted People or others; Also, Spying-Glasses of three Feet long; which are to set on a common Walking-Cane, and yet be carried as a Pocket-Book; all at the most reasonable Rates.—The New-York Gazette or the Weekly Post-Boy, May 21, 1753.

Interestedly, Mr. Bamper may have owned a glass shop and black smith shop at No. 24 Beekman St.

Glass House.—To be sold...The well known houses and lots of ground, with a large carpenter's and blacksmith shop of the late Lodwyk Bamper, deceased, No. 24 Beekman street New York...—New York Packet, January 26, 1787.

While the English in 1744 recognized her work prior to her immigration to America, after immigration, the French in 1762 claimed her instruments as being the preferred tool for exploring the microscopic world during the enlightenment. The author wrote politely pointing out how his Wilson dissecting microscope was a good enough copy of Susanna's cabinet mounted instrument. The one difference of the later Willson microscope being tweezers added to the base cabinet so to hold the specimens in place, as compare to putting it between slides/skeins like Sommer's microscopes. It is important to note that the cabinet top dissecting microscope post-dates Balthasar's active years. We can place the Sommer's version of handheld screw microscope in his court, while the cabinet top directing microscope in Susanna's.

Recommends... “de se servir du Microscope à Vis de Sommers & de Wilson, sans que l'on soit obligé de le tenir;” - Book: “Traite anatomique de la chenille: qui ronge le bois de saule” , by Pierre Lyonet, 1760

After the French and Indian war, on March 14, 1765, Susanna will die while being a member of the Moravian Church (est. 1741) in Bethlehem, Pennsylvania. When exactly she retired to PA, is unknown.

It is difficult to say just how many decedents can claim ancestry to this first of their kind American, but through Mary Elizabeth who appears to have had one child, Anasian Cooper, she can claim five grandchildren. It is unknown if Elizabeth who married a Moravian church pastor had any surviving children. Lea Susanna appears to have stayed in the Netherlands. According to the magazine De Nederlandsche leeuw, Maandblad van het Koninklijk Nederlandsch Genootschap voor Geslacht- en Xapenkund, which publishes genealogies there were a number of them. It is possible that she married into the Cornelis Michielsen Schimmelpenning family line who was born around 1557, though it is not clearly stated how she is related.  It made note of Lea Susanna's baptism in 1728 and who her parents were.

I do have one request form you all. I have been searching for examples of her work, but I believe her work may have been unsigned, at least for the smaller pieces. One modern historian of lenses sights having read/seen the initials "Juffrouw Sommert" as being used by Sommer, while B. Sommer is used while they are married. They turn up in old auction catalogs and museum inventories, though I could only source one photo. If anyone comes across a "sommer" scope, please add its location to the comments section.



Thank you !






Secondary sources:


Thinkers and Tinkers Early American Men of Science, New York, by S. Bedini, 1975, pp 215-216


The New York Genealogical and Biographical Record, Volume 52 , edited by Richard Henry Greene, Henry Reed Stiles, Melatiah Everett Dwight, George Austin Morrison, Hopper Striker Mott, John Reynolds Totten, Harold Minot Pitman, Louis Effingham De Forest, Charles Andrew Ditmas, Conklin Mann, Arthur S. Maynard

A History of the Moravian Church in New York City, By Harry Emulous Stocker

A Register of Members of the Moravian Church: And of Persons Attached to Said Church in this Country and Abroad, Between 1727 and 1754. Transcribed from a Ms. in the Handwriting of the Rev. Abraham Reincke, to be Found in the Archives of the Moravian Church at Bethlehem, Pa., and Illustrated with Historical Annotations, H. T. Clauder, printer, 1873.