Masonic Mathematics: The 47th Problem of Euclid

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Past Master's Jewel, 1823. Thomas Harper (ca. 1735-1832). London. 2017.018.2. Photograph by David Bohl.

Do you remember the Pythagorean Theorem? This geometric figure, also known as the 47th Problem of Euclid, represents the idea that the area of the two smaller squares created by using the lines of a right-angle triangle as bases is equal to the area of the largest square created in the same way. It is stated mathematically as c2 = a2 + b2 in which “c” is the hypotenuse (longest side) and “a” and “b” are the other two sides. Like many geometric expressions, it’s difficult to describe with words, but its meaning is fairly comprehensible visually.

Luckily, then, this symbol appears on Masonic aprons, jewels, pitchers, quilts, lantern slides, mark medals, tracing boards, and other decorative and ritual material in the collection of the Scottish Rite Masonic Museum & Library. Freemasonry draws symbols from a variety of sources, including geometry, to teach instructive lessons to its members.

This geometric figure has two names associated with some of mathematics’ historic giants: Pythagoras (ca. 570 B.C.E. – ca. 495 B.C.E.) and Euclid (ca. 300 B.C.E.). However, its roots reach back further. Babylonians (ca. 1900 - 1600 B.C.E) used it to solve geometric problems that involved right triangles. In Freemasonry, it is often called the 47th Problem of Euclid. This symbol is introduced in the 3rd or Master Mason degree.

The object shown here, an engraved Past Master’s jewel, bears a particularly compelling visual representation of this noteworthy geometric figure. English silversmith Thomas Harper (ca. 1735-1832) crafted this jewel, marking it with his initials and British silver hallmarks. The “leopard’s head” mark indicates that the silver was hallmarked in London after 1822. The lowercase “h” indicates Harper made the item in 1823, according to the “date letters” that were used in British silver.

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Past Master's Jewel, 1823. Thomas Harper (ca. 1735-1832). London. 2017.018.2. Photograph by David Bohl.

This form of a Past Master’s jewel featuring a right-angle square with a rectangle engraved with a depiction of the 47th Problem of Euclid, was popular in English lodges in the early decades of the 1800s. This style of jewel inspired Past Master’s jewels in Pennsylvania, which often have a right-angle square bearing a suspended rectangle with the geometric figure engraved on it.

This fascinating Past Master’s jewel is currently on view at the museum in "What's in a Portrait?" and in our online exhibition. You can see other items in the museum’s collection that bear the 47th Problem of Euclid on our searchable online collections database.

Please Pass the Butter! A New Acquisition

2014_021a-dDP1DBAs we always like to tell people, the Scottish Rite Masonic Museum & Library actively collects not just Masonic objects and documents, but items associated with all types of American fraternal groups.  Recently we purchased this butter dish, which is engraved on one side, “Pilgrim Lodge No. 75 I.O.O.F.”  Like many Masonic lodges and groups, other fraternities, such as the Independent Order of Odd Fellows lodge that owned this butter dish, often combined social activities, like a meal, with their meetings.  This butter dish may have been part of a set of serving dishes that the lodge purchased for use at group meals.  The dish was manufactured by the Wilcox Silverplate Company of Meriden, Connecticut, which was established in 1865 and merged with several other companies to become the International Silverplate Company in 1898.

Pilgrim Lodge No. 75 was founded in Abington, Massachusetts, in 1845.  After meeting for almost 15 years, during which time the lodge paid out about $600 for benefits and buried one member, the lodge surrendered its charter in 1859.  In 1871, the Grand Lodge of Massachusetts, I.O.O.F., reinstated Pilgrim Lodge No. 75.  At its first meeting, three members of the old lodge joined five members from Mattakeeset Lodge No. 110 and ten new initiates to begin a new era of its existence.  In 1873, the lodge purchased the town’s old high school building and fitted it up as a hall.  This may be when they purchased this butter dish, although it is impossible to know without more information.  Over the next ten years, members from Pilgrim Lodge went on to start Odd Fellows lodges in Rockland, Bridgewater and South Abington. 95_061_25DI1

A quick search of our collections database for “Pilgrim Lodge No. 75” also turned up a World War I ID tag, or “dog tag.”  Unfortunately, we do not know who the tag originally belonged to, but it is stamped with the Odd Fellows three-link chain and the words “Pilgrim Lodge No. 75 IOOF.”  World War I marked the first time that Americans fought after identification tags were made mandatory in the Army Regulations of 1913.  However, the serial number system was not adopted until 1918, so many World War I-era tags, like this one, do not include a number.

Independent Order of Odd Fellows Pilgrim Lodge No. 75 Butter Dish, 1871-1900, Wilcox Silverplate Company, Meriden, CT, Museum Purchase, 2014.021a-d.  Photograph by David Bohl.

Independent Order of Odd Fellows World War I Dog Tag, 1917-1919, unidentified maker, United States, gift of Jacques Noel Jacobsen Jr., 95.061.25.


D. Hamilton Hurd, comp., History of Plymouth County, Massachusetts, Philadelphia: J.W. Lewis & Co., 1884.

An Addition to the Collection: Mark Medal from Connecticut

Ezra Bennet medal 2013_054_1DP1DBWhen it rains it pours!  As noted in recent and past posts, we’ve got a soft spot for the personalized badges that some Masons commissioned for themselves in the first decades of the 1800s.  We are excited to have just added a wonderful Connecticut example to our collection at the Scottish Rite Masonic Museum and Library.

This silver medal belonged to Ezra Bennet (also spelled Bennitt and Bennett).  Born in 1776 or 8, Bennett appears to have been a life-long resident of Weston, Connecticut.  There he married Esther Godfrey (dates unknown) in 1796.  Counted in the 1810, 1820 and 1830 census, Bennet was probably a farmer.  He died in 1831 and was buried in Bridgeport, Connecticut.  Records at the Grand Lodge of Connecticut note him as raised at Ark Lodge No. 39 of Redding (now in Danbury) in 1802.  A local history names Ezra Bennet as a member of Lynch Chapter No. 8 and Heron Mark Lodge, along with his brother, Platt (b. 1770) and William Bennitt (dates unknown), likely another relation. 

First established in 1801, Lynch Chapter No. 8 and Heron Mark Lodge met in Weston and Redding until 1828.  Although located in Connecticut, where Royal Arch Masons first organized a Grand Chapter in 1798, Lynch Chapter No. 8, received its charter from the Grand Chapter of New York.  Interestingly, this charter is not named in the proceedings of the Grand Chapter of New York.  Joseph Wheeler, however, notes the source of Lynch Chapter No. 8’s charter in his history of Royal Arch Freemasonry in Connecticut.  Masons in New York founded numerous Mark Lodges—one scholar estimated over 80 through 1809—many warranted by the Grand Chapter of New York.  A great number of these New York Mark Lodges were independent—not affiliated with a Royal Arch Chapter.  Connecticut brethren also founded Mark Lodges—some scholars believe the one formed in 1783 at Middletown, Connecticut, was the first in the United States—but only a few.  Unlike their colleagues in New York, the Grand Chapter of Connecticut did not charter or administer independent Mark Lodges.  A few years after its founding, Lynch Chapter found a home with the Grand Chapter of Connecticut, when that group admitted the chapter “into full fellowship and unity.”

The original members of Lynch Chapter No. 8 named their group after a member, Francis Lynch (dates unknown).  In the same spirit, members gave the name of another locally-influential citizen, William Heron (1742-1819), to their Mark Lodge.  In addition to serving as the first Master of Ark Lodge in Redding, Heron was active in local and state government and holds the intriguing distinction of having likely been a spy for both sides during the American Revolution. 

Ezra Bennet mark side 2013_054_1DP2DBUnfortunately, we don’t know too much about Erza Bennet.  This medal, however, may give us a glimpse of what he valued.  Mark medals come in many shapes. The most popular ones were shields, hearts, circles and keystones.  Bennet’s medal was crafted in an uncommon teardrop shape that probably represented a plumb bob—the weight at the end of a plumb line.  In Freemasonry, a plumb or plumb rule, a tool that helps the user assess verticality, is a symbol of uprightness, rectitude or truth.  A level, which also incorporated a plumb bob, represented equality.  On one side of the this medal, the engraver cut Bennet’s name in a flowing banner decorated by stylized flowers and vines, similar in style to the engraving Peter Rushton Maverick (1755-1811) executed on the medal he made for Frederick Phile.  On the other side of the Bennet medal the engraver pictured four symbols, an all-seeing eye, a sun, a crescent moon and a heart, all within the mnemonic HTWSSTKS. Placed inside the mnemonic, together these symbols formed the mark Bennett chose for himself.  This mark likely recalled some of the lessons he learned in the lodge.  Ritualist (and fellow Connecticut resident) Jeremy Cross (1783-1860) included an illustration featuring those symbols, along with a comet and stars, in his handbook for Freemasons, The True Masonic Chart and Hieroglyphic Monitor. With the illustration, first published in 1819, Cross noted this interpretation of the symbols for his readers:  “…although our thoughts, words and actions, may be hidden from the eyes of men, yet that All-Seeing Eye, whom the Sun, Moon, and Stars obey, and under whose watchful care even Comets perform their stupendous revolutions, pervades the inmost recesses of the human Heart, and will reward us according to our merits.”

If you have any insights or questions about this recent addition to the collection, please leave us a comment.

Photo credit:

Mark Medal, 1801-1828. Probably Connecticut, Museum Purchase, 2013.054.1. Photos by David Bohl.


Case, James R., “William Heron,” The Case Collection of Masonic Notables (Fulton, Missouri: Missouri Lodge of Research, 1984).

Cross, Jeremy L., The True Masonic Chart and Hieroglyphic Monitor… (New Haven, Connecticut:  Amos Doolittle, 1820).  Reprinted by the Texas Lodge of Research, 1984.

Hurd, D. Hamilton, History of Fairfield County, Connecticut (Philadelphia, Pennsylvania: J. W. Lewis and Co., 1881).

Jack, Harold W., Mark Lodges of New England (Boston, Massachusetts:  The Massachusetts Chapter of Research, 1976).

Wheeler, Joseph K., Records of Capitular Masonry in the State of Connecticut (Hartford, Connecticut:  Press of Wiley, Waterman and Eaton, 1875)

Hancock Church Silver in “Sowing the Seeds of Liberty”

Among the many treasures on view in “Sowing the Seeds of Liberty:  Lexington and the American Revolution” are some wonderful examples of communion silver.  Residents of Lexington first used them to take communion as part of their worship over 240 years ago.  In addition to playing an essential role in the service, these cups, associated with different members of the Hancock family, were fashioned to be enduring memorials.

In the 1700s in Lexington and other New England towns, only church members took communion from these during Sunday services. Not all who attended the First Church in Lexington were members. To become a member, a man or woman needed to publicly confess their transgressions and be saved.  During that time, in Congregational churches, church goers commissioned communion silver that could be passed easily from hand to hand.  As well, they selected forms based on the kinds of vessels they used in their own in households, including beakers and cups like these.   Although these forms may have been familiar to Lexingtonians, the fact that they were crafted of a precious metal made them anything but ordinary.

EL99_001_11a-bT1 On a gray day, polished silver would have glinted, shone and added glamour to the meeting house.  In addition to their aesthetic properties, the monetary value of these cups ensured they were well looked after.  In fact, these cups may have been among those cared for by the elder church deacon, Joseph Loring (1713-1787), at his home in 1775. On April 19, still in shock from the morning's battle, Lexington residents worried that British soldiers might loot homes on their way back from Concord. To protect her family's and the church's valuables, the deacon’s daughter, Lydia (b. 1745), hid these portable valuables under a pile of brush behind the house. She was smart to have done so.  British soldiers pillaged the Lorings' home and burned itto the ground, but Lexington did not lose its communion silver. 

Both of these cups both memorialize Hancock family members.  Successful Boston businessman Thomas Hancock (1703-1763) grew up in Lexington. He was the son of John Hancock (1671-1752), the town’s first minister. Upon his death, he left £20 to his father’s former church, specifying it be used to make “two silver cups for the communion table.”  Thomas Hancock, with his wife Lydia, raised his nephew, also named John Hancock (1736/7-1793).  The younger John Hancock later served as the President of the Continental Congress and in that capacity added his now-famous signature the the Declaration of Independence.   
EL99_001_7S1 small Also a son of the Reverend John Hancock, Ebenezer Hancock (1710-1740) followed in his father’s footsteps and served as his assistant for six years. He died at the age of thirty, possibly in a diphtheria epidemic.  Made of valuable, long-lasting material and permanently marked with his name, this present to the church endured well after the memory of Ebenezer’s contributions to town life faded.

The National Heritage Museum is grateful to the First Parish Church of Lexington, Unitarian Universalist, for the loan of the communion silver that helps tell the story of April 19, 1775.


Footed Cups, 1764. Nathaniel Hurd (1729/30-1777), Boston, Massachusetts. Loaned by First Parish Church of Lexington, Unitarian Universalist, EL99.001.011a and.011b. Photograph by David Bohl

Beaker, ca. 1740. Jacob Hurd (1702/03-1758), Boston, Massachusetts. Loaned by First Parish Church of Lexington, Unitarian Universalist, EL99.001.7. Photograph by David Bohl