Born on the grounds of her father’s zinc factory, Mary Hegeler Carus took the unusual step for a woman of her time period in pursuing a college career and going on to advanced study in engineering. She then took on the responsibility of running her family’s business, the Matthiessen and Hegeler Zinc Company, resisting the efforts of her siblings to sell the company to outsiders.
Born on the grounds of her father’s zinc factory, Mary Hegeler Carus (born: January 10, 1861 in La Salle, IL; died: June 27, 1936 in La Salle, IL) took the unusual step for a woman of her time period in pursuing a college career and going on to advanced study in engineering. She then took on the responsibility of running her family’s business, the Matthiessen and Hegeler Zinc Company, resisting the efforts of her siblings to sell the company to outsiders. Nor was she a figurehead: while she had a long and happy marriage, she did not follow the pattern typical for her period of female inheritors turning over company management to their husbands but instead was actively involved in all aspects of company policy. By the time Carus died in 1936, zinc had become an integral component of many of the 20th century’s most important consumer products from radios to automobiles.
January 10, 1861 was an eventful day in American history. Newly-elected Abraham Lincoln watched as his wife Mary climbed aboard a train in Springfield bound for the White House, where she would begin the process of re-decorating in anticipation of his inauguration. Senator William H. Seward accepted Lincoln’s offer of a Cabinet seat as the Secretary of State. There was a rumor reported in the Chicago Tribune that the Confederacy had fired cannons at the side-paddle steamer Star of the West as she tried to enter Charleston Harbor, which was true, and that Major Robert Anderson on Fort Sumter had fired back, which was not. And it was on this day in the tiny town of La Salle, on the Illinois River, that Marie (Mary) Henriette Hermine Hegeler was born on the factory grounds of the Matthiessen and Hegeler Zinc Company.
To say that the little girl was brought into a unique environment would be an understatement. Her father, Edward Carl Hegeler, had a fascinating and tragic childhood before becoming a pioneer in Illinois. Born in Bremen, Germany on September 13, 1835, his mother, Anna Katerina von Tungeln, died of puerperal fever when he was three, on April 17, 1838. His father made sure he was classically educated within the Pietistic faith at the Schnepfenthal Institute in Thüringen. When he was twenty Edward Hegeler was orphaned when his father committed suicide on January 12, 1855 to end his struggle with colon cancer. Because he was technically still a minor Hegeler was placed in the care of his brothers and brother-in-law, who operated a trading company in Bremen, Hegeler & Söhne, which is still in existence. They decided that the study of mechanical engineering suited his aptitudes and thus sent him to the Polytechnic Institute of Hannover. He went to complete a course at the prestigious Bergakademie Freiberg, the oldest school of mines in the world. It was there, while studying under Professor Julius Ludwig Weisbach, that young Hegeler made some critical friendships which would last him, and his daughter Mary, for the rest of their lives.
The most important connection was probably with the professor himself. Weisbach was by then famous for his influential book New Mine Surveying Techniques and Their Application in the Rothschönberger Tunnels of Freiberg, which established him as one of the founders and leading lights of the science of mine surveying, as well as for his textbook for mechanical engineering students, Textbook for Engineers and Machine Mechanics, which showed him to be a mathematician of note as well. Weisbach’s most important contribution is the Darcy-Weisbach equation, which is still used to this day to calculate friction loss in pipes. Weisbach’s influence on Hegeler’s life cannot be overstated, but Hegeler was also drawn to Weisbach’s daughter Maria Camilla. Hegeler became engaged to Camilla almost immediately, but it was to be a long and secret engagement because her parents opposed the idea. Hegeler’s father had been the German consul to the United States and had taken him to New York City as a child. Young Edward made no secret of wanting to go back to America and the Weisbachs were vehemently opposed to allowing their daughter to accompany him.
His other important friendship was with Frederick William Matthiessen, a fellow student who had the allure of also having visited the United States. Matthiessen was born March 5, 1835 in Altona, near Hamburg, and would remain Edward’s friend and business partner for life, dying in 1918, eight years after Hegeler, and being buried in the same cemetery in La Salle. Mary would find herself dealing with him and his heirs during her entire lifetime. Because of their mutual belief in the bright prospects of the American nation the two young engineers immigrated to the United States in late 1856 and immediately set out in search of a place to set up a zinc smelting operation using the specialized knowledge they had gained in Freiberg. With expertise garnered in Weisbach’s mine surveying course, they first demonstrated that they could produce zinc at the Lehigh Zinc Company near Bethlehem, Pennsylvania but eventually decided upon La Salle as the ideal location because of both its coal fields and its proximity to the zinc ores of Missouri and Wisconsin. By Christmas Eve 1858 the “first shovelful of dirt was turned” and two years later, in early 1860, Hegeler headed back to Germany to convince the Weisbachs to allow him to marry Camilla. On April 5, 1860 they were wed.
By the time Mary was two years old the importance of zinc was changing. Although it was primarily used to give iron a protective coating, the Civil War was creating a large demand for zinc in the manufacture of weapons and brass cartridges and Hegeler and Matthiessen had begun to perfect their experiments with smelting techniques. The process at that time was very labor-intensive. It involved the use of either a “Belgian” or a “Siemens” furnace. These furnaces were used to “roast” zinc ore to burn off sulfur in containers called “retorts,” which lay horizontally inside the furnace with their open ends protruding out. When heated to around 2000 degrees Fahrenheit zinc vapor is created and condenses into the metal. Both the charging of the retorts and the drawing off of the liquid metal is done by hands skilled in this dangerous and hellish work. According to family histories, Mary Hegeler was her father’s constant companion as he toured the furnaces and she took on responsibilities from a young age. In a time when, as her great-granddaughter Kate Carus writes, “smelting zinc was as much an art as a science,” one important task was for Mary to “go from furnace to furnace on the factory floor to evaluate the flames for her father. Based upon her recommendations, modifications to the furnace’s operation would then be made.” This prompted Carus to call her “an accidental engineer.” It must have been a remarkable sight to the workmen to see a young girl walking through the factory in full Victorian dress to tell her father whether or not a furnace was adjusted correctly.
Although she attended the public schools in La Salle, Mary’s education was anything but ordinary. By the time she was sixteen she was working in the factory’s all-important assay office, which was where the purity of the zinc was tested, and there was very little the young lady could not do at the works, which by then had grown significantly. “The trust that Edward Hegeler had in his young daughter’s technical and managerial abilities helped give him the freedom to pursue his inventions while assured that he had adequate oversight on everyday plant operations,” Kate Carus writes. Among the inventions Edward Hegeler patented were new types of furnaces that could produce zinc oxides and produced sulfuric acid as a byproduct.
In fact, Hegeler’s finances had improved so dramatically by 1874 that he could undertake the building of a mansion to house his growing family, which would include nine more children. He commissioned the eminent Chicago architect William W. Boyington to create a home for him in keeping with his new status in the community. Boyington had designed such notable structures as the original campus of the University of Chicago and would later complete the new state capitol building in Springfield. For the interior Hegeler selected the noted Chicago designer August Fiedler. Soon the family would be living in an Italianate home with a Second Empire roof, erected with bricks and limestone, but with a concrete facade made of Portland cement, a new technology of the time, fashioned to look like stone blocks. By the spring of 1877 the mansion had been completed and the family moved in; Mary lived in the house until she left for college and would later return to live in it for the rest of her life.
Although her father used new technology on the exterior, commissioning Fiedler meant that the interior would be an Old World masterpiece. Fiedler was renowned for his ability to design furniture and cabinetry out of exotic woods and by 1877 his client list would include Marshall Field, Joseph Medill, and William Boyington himself. His work “created warm and inviting designs with classically-inspired carvings and rich inlaid wood panels. His work turned an ordinary mansion into something artistically exceptional.” Gustav Körner, a frequent guest of the Hegelers, described their home and that of the Matthiessens as “handsome… [and] filled with large and elegant libraries, paintings, engravings and bronzes. Their residences are surrounded by fine lawns and parks. Gymnasiums, billiard rooms, ten-pin alleys, and in fact everything that is now called “modern improvements” are to be found in these almost palatial residences.
Although Mary would become a young woman in these refined surroundings she was not sheltered from the obstacles her father faced in his business career. For example, when she was nine she witnessed her father and Matthiessen fight out a lawsuit against them for over $3,000, with interest, by the West Engine Company of Morristown, Pennsylvania ($50,000 in 2010 dollars). The plaintiffs alleged that they had delivered zinc rolling machinery to Matthiessen and Hegeler in 1866 and had not been completely paid for it. Although Hegeler and Matthiessen’s counter-claims in this case were ineffective, young Mary saw her father victorious in a different case in 1876, when he and Matthiessen successfully sued the Northern Illinois Coal and Iron Company for trespassing upon their land, winning themselves 45 acres of coal in exchange for 23 acres the company had illegally mined. Because of her close working ties to her father’s business Mary gained valuable insights into American courts that she would use to great advantage later.
Legal wrangling wasn’t the only educational experience Mary would get in La Salle. Her ethno-political experiences would be remarkable because of the climate her father and Matthiessen had begun in. During the very time that they were erecting their first factory in Illinois, Abraham Lincoln was wholeheartedly engaged in winning over the German voters of the United States. Hegeler and Matthiessen would have closely watched these political maneuverings and it would have filled them with a sense of their importance. If Abraham Lincoln courted Germans, then America was really a great place for them to be. At the time of Lincoln’s election there was great emphasis placed on the role the German vote had played in the Republican victory. Having grown to middle age in an area saturated with Germans, Lincoln actively courted them as a counterweight to the Irish vote for Stephen Douglas, going so far as to secretly purchase a German-language newspaper in 1859.
With the memory of princely oppression in their homeland and the knowledge of the brutal reaction to the 1848 revolution, elite German-Americans like Hegeler and Matthiessen welcomed the fight against slavery and, in general, wholeheartedly supported Lincoln and the Republican Party. With this kind of ethno-political experience in America it is no surprise that in August of 1872 her father became a Liberal Republican candidate for the Illinois State Senate. The Liberal Republican movement had sought to address discontent with the Grant administration and although her father wasn’t elected, Mary undoubtedly heard about his political battle with one of Abraham Lincoln’s important German friends, Dr. Theodore Canisius, a physician and the Republican editor for whom Lincoln had secretly purchased the German newspaper. Mary would have proudly read in the Chicago Tribune that when her father rose to debate Canisius the “doctor and his small band fled the hall, and a rousing Liberal meeting closed the evening’s entertainment.” To rout a man like Canisius was an important achievement among the Germans of Illinois. He had been Lincoln’s standard-bearer among Illinois’ German-Americans during the critical 1859–1860 period and was generally recognized as the man Lincoln trusted to convey his message to this specific community. He had been rewarded by Lincoln after the election by being named the United States consul to Vienna.
But political battle wasn’t the only thing Mary would have read about her father in the pages of the Chicago Tribune. Just a month later, responding to Hegeler’s official statement that the “sale of arms and ammunition to the enemies of my fatherland without provocation has offended my national pride, that of a German citizen of the United States,” the Tribune reported the Ottawa Republican’s “crushing reply” suggesting that Hegeler move back to Germany if he was so offended. While undoubtedly a bit of retribution for causing the retreat of Dr. Canisius, the Republican’s attack was also linked to American political jealousy over the power enjoyed by German voters. Although based upon a largely mistaken belief in German-American political unity, this perception had been shared by none other than Abraham Lincoln himself. These types of lessons would serve to embolden and toughen the young girl to take part in the male-dominated arena of American business and politics.
When the boundaries of her education in La Salle had been reached the young Mary Hegeler decided upon a college education, something relatively few women could hope for at this time. As a wealthy young woman in 1878 there is something to be learned from her choice of the University of Michigan, which began admitting women in addition to men in the 1870s, rather than an all-women’s college. At Michigan, Mary involved herself in the traditionally male subjects of mathematics and chemistry and was the first woman to graduate from the Engineering College in 1882. Her college mementos include pressed flowers she saved from dances, suggesting she was not ostracized for her choices.
Mary was eager to experience a higher level of education than that available to her in America. Undoubtedly influenced by both her father and mother she undertook the journey to Germany and in 1885 began attending the Bergakademie Freiberg. She had two family members on the faculty, her uncle Albin Weisbach and her cousin Clemens Winkler, who both wrote letters recommending her admission. Winkler, however, had to guarantee that she would have separate laboratory facilities so that she would not disturb the male students, an example of contemporary practices in which women were both part of the scientific community and simultaneously excluded from it. Her transcripts show that over the three terms, or one full year, of classes she attended she earned “a 10 (the highest grade possible) for all but one course in which she earned a 9.”
In fact, in 1886 she was working in the laboratory of her cousin, Clemens Winkler, when the final purification of the metal which came to be called germanium was achieved. Notwithstanding her connections, Mary was not allowed to receive a degree upon completion of her coursework because she was a woman. After finishing her year of courses she traveled in Europe, taking the grand tour that was considered an obligatory part of the enlightenment of wealthy young Americans. With her education complete Mary returned to the United States in 1887 and soon went back to work in her father’s business as a full member of the board of directors.
Although Mary Hegeler had been raised from childhood in and around the zinc works, even she must have been amazed at what Matthiessen & Hegeler Zinc had become. Situated upon fifty acres, the company had developed into the largest zinc smelting operation in the United States, a “lucrative monopoly” according to the author of an 1888 full front-page spread, complete with illustrations, in the Chicago Tribune. Although the company had a minor rival in the Illinois Zinc Company, also located in La Salle, its most important competitors were the giant works of Europe. In 1880, while Mary was at Michigan, Hegeler and Matthiessen added an important new process to their repertoire. Frederick Matthiessen’s brother had become involved in the Glucose Manufacturing Company of Chicago, which used sulfuric acid in the manufacture of the sweetener glucose. The sulfur produced as a byproduct of smelting zinc, which had traditionally been discarded as waste, suddenly became profitable if it could be converted into sulfuric acid. Hegeler perfected a method for this and soon the company had erected new buildings for the work containing two acid tanks 16 feet tall, 21 feet wide, and 468 feet long, built of nearly 1,000,000 pounds of lead. As an added benefit, Hegeler and Matthiessen began selling another byproduct of their new process, sulfate of soda, to local glass factories in the area. On the darker side, they were forced to construct an enormous chimney, 257 feet high and 28 feet in diameter, to carry away the poisonous acid fumes. It was the most prominent landmark in the region. By the time Mary Hegeler came back to work for her father they were producing 30 tons of the “king of acids” a day.
Mary would also have been shocked at the new levels of zinc her father was producing. The works now had somewhere between 700 to 800 men working, and some departments functioned around the clock; every twenty-four hours they created between 35 to 40 tons of spelter, the great majority of which was rolled into zinc sheets. By the time she returned home the Chicago Tribune was estimating Hegeler’s worth, as president of the company, at around $10 million ($230 million in 2010 dollars), with an annual income of around $100,000 (or $2.3 million in 2010 dollars). In addition to manual labor, a friend of the Hegeler family noted that the company’s technological complexity meant “quite a number of highly educated gentlemen are employed by this firm as superintendents, geologists, and metallurgists.”
The Tribune complained about the partners’ “reputation among newspapermen of declining to be interviewed for the benefit of the public or of anyone else, which they have ever strictly maintained.” In fact, prior to writing their front-page exposé, the Tribune sent a reporter to see the “leading photographer” in La Salle to procure images of these two “exclusive people.” They were informed that he had “never seen a picture of either of them. No photographs have ever been taken here, although they have been applied to many times to sit.” The photographer opined that they “are afraid as death that if they did so the pictures would get into the newspapers.”
Another surprising discovery must have been the volatile political situation and how Americans were analyzing the business practices of the two entrepreneurs. In the wake of the Haymarket bombing in Chicago two years earlier it is no wonder that Matthiessen and Hegeler’s “foreign” workforce would come under some criticism. In the beginning the partners imported their workers from Belgium and Poland, but since “strikes among the foreign element became dangerously frequent in La Salle,” the Tribune claimed, the system was “abandoned.” The Tribune also claimed that the two engineers hired only men from “the old country” and “it is their boast that they do not have a native laborer on their works,” and commented drily that “their workmen live in ‘homes’ that are little better than huts.”
Mary undoubtedly read the vicious attacks and accusations made against her father and his business partner. An anonymous writer, using the nom de plume “E pluribus unum,” wrote a scathing indictment of the two which the Tribune published half a month later. The author purported to inform readers of “a few facts in regard to this peculiarly European enterprise, which has succeeded here, so far, in amassing great wealth at the expense of all regard for anything that would have elevated its employees, or the public.” Sounding suspiciously like someone from the rival La Salle Zinc Company, the author claimed that Matthiessen and Hegeler were unceasing in their efforts “to crowd every man to his utmost ability 365 days in the year— a cruelty to man and beast.” The writer claimed that the La Salle Zinc Company had a “beautiful mill much superior to theirs in outward appearance (for they have no regard for adornment, always running a tumble-down looking affair),” and that “they have lost an opportunity their posterity will regret.”
The writer of the letter asserted that the company was involved in a secret plan to mine the coal beneath La Salle’s streets, and that Frederick Matthiessen had been elected the mayor of La Salle in April of 1887 purely to facilitate those nefarious designs. Asserting that “this European city is under monarchical government,” the writer claimed:
They have fine palatial residences here, but they can only say,
Selkirk-like, and cut off from any true American citizen—
I am monarch of all I survey,
My right there is none to cajole,
From the centre all round to the bay
I’m lord o’er Irish, Saxon, and Pole.
If Mary was disturbed by these attacks upon her father it might go a long way towards explaining the extremely private direction she took later in life. Mary’s involvement in the family business increased dramatically when her brothers, Julius and Herman, made overtures of selling the business while Edward Hegeler was vacationing in Europe in 1902. This discovery made Hegeler furious enough to give his sons their share of their inheritance and send them on their way. Mary became the president of M&H in 1903 and the brothers started their own zinc company in Danville, Illinois in 1906. After this point her father concentrated exclusively on his religious and philosophical interests and Mary became a real power in the company.
Edward Hegeler and Frederick Matthiessen had always shared the stock of the company equally, and had made a verbal agreement that a Hegeler would always serve as president and a Matthiessen as secretary. Under its organization as an Illinois corporation in January 1871 for a fifty-year term, the partners had capitalized their stock of 426 shares at a value of $426,000 ($7.85 million in 2010 dollars), or $1,000 per share, and divided them equally. Upon his death in 1910, Frederick Hegeler conveyed his 212 shares to Mary with instructions that she was to hold them in trust for his other surviving daughters. This was a classic arrangement for situations in which no male heir was ready to serve as successor. Women were traditionally seen as interim entrepreneurs and stewards of family wealth. The Matthiessens obviously viewed Mary this way for at a directors’ meeting in 1913 they attempted to end Mary’s presidency of the company by voting one of their own to that position. Mary and her brother-in law, Christian Bai Lihme (the husband of her sister Olga), stormed out of the meeting. The battle for control over the company moved to the Illinois courts. Although she lost the battle over the 1913 directors’ election, she won other court battles and eventually prevailed. One of her first counter-offensive strikes ended successfully. For the purpose of having the required amount of directors, Mary was authorized to transfer one or two shares to individuals for that purpose, giving them ownership of the stock merely for the purpose of serving as directors, and being paid 15% of the profits of the corporation for their services. On February 27, 1913 Mary gave one share of stock to Christian Bai Lihme and began to hold separate board meetings with him. The Matthiessens began legal proceedings, which eventually made their way to the Illinois Supreme Court.
An affidavit filed during the course of these legal battles illustrates Mary’s role in leading the company. It states that M&H Zinc was a corporation with at least $6 million in assets (the equivalent of $123 million in 2010 dollars). Nine hundred men were employed there. She was a member of the two-person “Managing Committee,” which possessed “full executive control of all the business of the Company.” As such she “passed on all reports” of every department of the combined corporation. For example, “if a new engine or boiler is to be purchased, Mrs. Carus passes upon the specifications and bids and with the other member of the Managing Committee has the final determination.” The plans for new buildings were submitted to her. Everything fell under her authority, from the digging of a deep well to the construction of new furnaces; from water plants and mine escape shafts to the purchase of new coal land. She decided on wages and new laws affecting the company, and closely examined bank statements. She ruled on the question of “changing the motive power from mules to electricity and the kind and price of electric locomotives”. She approved the methods of fire fighting in the mines and decided on changing the hoisting apparatus from steam to electricity. In addition, she was a director in the La Salle & Bureau County Railroad, and when legal opinions were asked about the validity of contracts “these opinions are submitted to her and she can pass upon them intelligently.” The La Salle & Bureau County Railroad, which the partners started in 1890 and finished in 1893, was a ten-mile-long road from La Salle to the Illinois River and served as an important transportation link for the company. The affidavit also showed she was careful with her finances outside of M & H Zinc. Mary was also careful with her own finances. For example, her father had given her $600,000 in 1900 ($16.1 million in 2010 dollars) and named her as the trustee of the Open Court Publishing Company. By the time of the attorney’s affidavit mentioned previously she had managed to build that amount to $800,000, and was personally worth $1.25 million (or close to $15 million in today’s dollars).
The Supreme Court of Illinois upheld Mary’s actions, rejecting the Matthiessens’ claim that Lihme was only a “sham” stockholder. After these fights, “the two families managed to get along for several years, until 1924, when, during an executive reorganization, the Hegeler family (now dominated by Carus family stockholders) bought out the Matthiessen side.” Meanwhile the zinc industry was undergoing a series of booms and busts. Mirroring the Civil War experience, when zinc had been in high demand for weapon cartridges, zinc was an important component of a wide variety of war materiel in World War I, used in everything from packing cases for ammunition to sheet steel used as boiler plate in ships. Zinc was also still used in weapons: an 18-pounder shell, one of the most widely-used types, for example, required some six pounds of brass containing two pounds of zinc; by 1916 some 25 million shells had been ordered from U.S. manufacturers by the British and French militaries. The American zinc industry was particularly important to the Allied effort because the bulk of European zinc production was in areas controlled by Germany. From 1914 to 1916 the value of American zinc exports increased more than twelvefold, from $23 million to $335 million (from $518 million to $8.8 billion in 2010 dollars). There was a slump in demand for zinc after the war but by the mid-1920s zinc metal production expanded again, driven in part by demand for a variety of consumer goods. The most significant use of zinc was to create galvanized steel auto parts that would resist rusting. In addition, early radios used zinc-carbon batteries and zinc-oxide semiconductors; zinc oxide was also used to manufacture solid rubber tires that could withstand heavy loads without the rubber melting and collapsing, a critical necessity that enabled the growth of the trucking industry.
As with most second-generation immigrant children, Mary Hegeler Carus’ identification of herself was as an American, and the conflicts she witnessed must have left her deeply conflicted between who she was and who her father was. This is certainly one of the most reasonable explanations for the way she shunned public attention when she got back from Europe. Having been born upon American soil her sensibilities may have been different from those of her father and his partner Matthiessen. While this is certainly a reasonable explanation, there was someone roaming the halls of the mansion in 1887 who would forever change her life, and who would open up an entirely different world for the young and gifted woman.
Paul Carus was born on July 18, 1852 in Ilsenburg am Harz, Germany, the son of a Protestant minister. He attended the public Gymnasium in Posen and then Stettin, where he came under the tutelage of the polymath Hermann Günther Grassmann. After graduation from the Stettin gymnasium Carus studied at the University of Strasbourg and then earned his Ph.D. from the prestigious Eberhard Karls University, Tübingen. Carus concentrated his studies in philosophy, natural science, and classical philology. Upon receiving his doctorate in 1876 he took a position as a professor at the Dresden Military Academy, but his liberal pamphlets gradually got him into trouble in Bismarckian Germany. He emigrated first to England but in 1883 decided to come to the United States, arriving in New York around 1884. He soon found his way to Boston’s Free Religious Association, publisher of a cash-strapped publication known as The Index. Hegeler, who corresponded with Benjamin Franklin Underwood, the Index’s editor, brought Underwood to La Salle to edit The Open Court, a journal he was starting to promote Monism, the religion to “supplant the traditional Christianity” that Hegeler believed could “offset the deleterious effects of agnosticism.”
Although at one point both Underwood and Carus worked at The Open Court, there was a falling out between Underwood and Hegeler. Carus was asked to step in and become the new editor of the journal. Hegeler even went so far as to hire him to take on the task of tutoring his younger children. Handsome, erudite, and charming, Carus apparently swept Mary off her feet while she was helping him with his English, a task their youngest son Alwin claimed her father had asked her to undertake. They were married on January 30, 1888. A new phase of Mary Hegeler’s life had begun. The couple had a lively emotional and intellectual relationship; Alwin would later recall his enjoyment at watching them in animated conversations. Although she was later seen as not being very loving towards her husband upon his deathbed, one hint of the couple’s deep love for each other is the story that Paul’s bedroom was locked after his death in 1919 and left exactly as it was when he died.
Mary’s introduction to the world of motherhood would begin with a crushing blow when their first child, named Robert, died at birth. But the tragedy of her first-born’s death did not hinder Mary or Paul. Six other children would follow in succession—Edward (1890–1975); Gustave (1892–1961); Camilla (1894–1954); Elisabeth (1896–1991); Herman (1899–1993); and Alwyn (1901–2004). Mary was a devoted mother, personally overseeing the education of her children. William T. Barnes, a grandson, remembers her as being kind and generous, but distinctly reserved. In her letters to her children one of the most often used phrases refers to enclosing a check. Mary’s letters to her sons Edward and Gustave while they were attending the University of Wisconsin are full of motherly concern. She wrote to Edward about his education, especially his examinations, and her letters were very attentive to his everyday needs. For example, in her letter of June 7, 1909, she reminds him that he “had best bring back your blanket and the sofa pillows so they may be washed.” On October 4, 1909, she wrote that she hoped he “may soon be settled,” and that she had found “two soft rugs which I thought might make your room seem brighter.” “Pace yourself,” she wrote him in November of that same year, “to get the beauty of it. So be sure and take things easy, and be out of doors all you can.” The younger siblings would often include their own letters to their brothers. Taken as a whole, the letters to Edward and Gustave don’t contain anything in the way of serious intellectual discussion, but there can be little doubt that Mary was a very loving mother. And although she was always deeply concerned about their rooms, books, and examinations, she never failed to express her desire that they be out of doors enjoying life, as she wrote to Edward in January of 1912, “I wish you might be able to skate and toboggan.”
During World War I, when it was prudent for German-Americans to keep out of the public eye, Mary made sure that every soldier enlisting from the La Salle and Peru area received a woolen blanket when he left for camp. Nonetheless her husband Paul’s publication, The Open Court, fell under federal suspicion for allegedly being “pro-Central Powers.” The Carus family was personally touched (though they may not have realized it) by the era’s anti-German hysteria: in August 1918 the U.S. Bureau of Investigation staged a blackout at the family’s Michigan summer house so that an agent could accompany an electrician to the house and search each room for alleged German propaganda. “The rumor that there is a full sized picture of the Kaiser on one of the walls of this house… failed to materialize,” the agent later reported.
In spite of generating great income during the “Roaring Twenties,” when automobile manufacture pushed up the demand for zinc, Mary had not foreseen the economic collapse that occurred in 1929. Soon she watched as the Great Depression decimated the corporation’s ability to pay off the 6% gold bonds it had issued to recapitalize after buying out the Matthiessens in 1924. M&H Zinc had to file bankruptcy in 1935 and suffer reorganization, but the company would be saved and continued to operate under the family’s control after her death. Her children also felt the bite of the collapse. On April 10, 1935 her son Herman, then a superintendent at M&H, was in a Chicago federal court joining Francis I. DuPont and others in testifying against Frank P. Parish and the directors of Missouri-Kansas Pipeline Company. In this $35 million bankruptcy Parish and three others had been charged with mail fraud. Herman related how he had lost $7,125 when the price of Missouri-Kansas Pipeline Company stock collapsed in the wake of Black Tuesday.
Mary had always maintained a low-key lifestyle in spite of her wealth. She wouldn’t even allow Paul Carus, an avid photographer, to capture an image of her. She was rarely to be found in the high society, which members of her family occupied, and her tastes were simple in an age Thorsten Veblen had characterized in his The Theory of the Leisure Class as a period of “conspicuous consumption.” Although the names of her siblings and children abound in the society pages of the Chicago Tribune, anecdotal evidence suggests she was generally content with playing solitaire in a room full of children playing, and that one of her chief joys in life was philanthropy. She and Mrs. George A. Wilson, Sr. established the La Salle Industrial School, for example, to provide job training for the town’s children who would not go on to college. One symbol of her continued interest in pure research was her decision to fund the publication of a series of books, the Carus Mathematical Monographs, from 1925 onwards, intended to be accessible to both mathematicians and the general public.
Because of her intensely private lifestyle little attention was paid when sometime early in 1936 Mary quietly took to her bedroom. She had apparently begun feeling ill, and yet her condition had not been deemed serious. Consequently, her death on June 27, 1936 came as something of a shock to her family and the community. At her funeral she was showered with superlatives which likely would have made her blush in protest had she heard them. At her simple and private burial in Oakwood Cemetery a quartet sang Luther’s “A Mighty Fortress is our God” in German before the Reverend Paul Brauns, pastor of the Zion Evangelical Church in Peru, delivered the eulogy. One of Mary’s closest friends for years, he was unashamed in saying that:
Great and good women like our departed sister should have their monuments not merely in the mute and icy marble, but in the warm, living hearts. Our departed friend is not dead. She had just begun to live. God has given to her a twofold life the life of the glorified and the life of an undying memory in the hearts of all who knew her and her generous heart. I believe we are commemorating today the life of a woman who looks larger now than when she died. There are reasons for this. One was her exceeding quietness; she sounded no trumpets made no noise, called no attention to her doings. She was a quiet woman in all her activity: quiet in her natural shrinkage from publicity or any kind of self-advertisement.
Like some long, swelling wave that rises on the dark bosom of the deep until it crests in whiteness and at its climax flings its crystal toward the sky, our sister’s life, gathering volume and value through all the years now at its summit breaks into the heavens. From the zenith of attainment and the top of action she passes to render her account to her Master.
Her best and truest eulogy is that she had a vigorous intellect, sustained by lofty purposes, and based upon an honest and feeling heart.
The story is told that when the Wobblies marched down from Chicago in 1912 to begin organizing at M&H Zinc the workers and their families surrounded the plant and the Hegeler and Matthiessen homes and told the I.W.W. they weren’t needed in La Salle. Thus it was fitting that Mary Hegeler Carus was carried to her grave by the supervisors she had worked with at Matthiessen & Hegeler. One set of hardened hands belonged to Charles Vohs, the master mechanic at the plant. Another belonged to Julius L. Whalen, the furnace foreman. There was Hesler Larson, the assistant superintendent of the rolling mill; Karl Langham, foreman of the acid, refining, roasting and cindering departments; Karl Kleimenhagen, superintendent of the Carus Chemical Works, and Herman Dickman, foreman of the La Salle and Bureau County rail-road yards. While the town lay still in the eerie quiet of the closed works, these work-toughened men gently took Mary to rest in a casket made of the finest zinc they could produce. In many ways her life was as refined and pure as the metal which dominated her world from the cradle to the grave.
 Katherine Helm, The True Story of Mary, Wife of Lincoln (New York: Harper, 1928), 153.
 Chicago Tribune, January 10, 1861.
 Julius Ludwig Weisbach, Handbuch der Bergmaschinenmechanik, 2 vols. (Leipzig: Weidmann’sche Buchhandlung, 1835/1836); Lehrbuch der Ingenieur- und Maschinen-Mechanik (Braunschweig: Friedrich Vieweg und Sohn, 1846–1868); Die neue Markscheidekunst und ihre Anwendung auf die Anlage des Rothschönberger Stollns bei Freiberg (Braunschweig: Friedrich Vieweg und Sohn, 1851). See also Wolfgang Küchler, Julius Ludwig Weisbach (1806–1871). Erzgebirgische Heimatblätter 1, 1994, pp. 8–10 and Bernd Schreiter, Julius Weisbach – Mathematiker, Markscheider und Maschinenkundler (mit Ahnenliste) (Arnsfeld: Verlag Bernd Schreiter, 2005).
 Kate B. Carus, “Marie Hegeler Carus—An Accidental Engineer” (conference paper, 1999 International Symposium on Technology and Society: Women and Technology—Historical, Societal, and Professional Perspectives, New Brunswick, N.J., July 1999).
 See Matthiessen & Hegeler Zinc Company, 1858-1958: Our First Century of Service (Privately Published, 1958). See also Michael E. Lenzi, “Zinc Comes to La Salle and Peru: A Historical Geography of the Matthiessen and Hegeler Zinc Company and the Midwestern Zinc Industry,” in The Industrial Revolution in the Upper Illinois Valley: Studies on the Illinois & Michigan Canal Corridor No. 6, ed. Michael P. Conzen, Glenn M Richard, and Carl A. Zimring, (Chicago: Committee on Geographical Studies, University of Chicago, 1993), 120.
 Frederick W. Matthiessen quoted in Chicago Tribune, June 5, 1910.
 Carus, “Marie Hegeler Carus.”
 The other children were: Helene (1862–1868); Camilla (1863–1955); Meta (1865–1868); Julius (1867–1943); Gisela (1869–1892); Herman (1872–1913); Annie (1873–1951); Zuleikha (1875–1962); and Olga (1877–1956).
 Raymond Lohne, “Founded at the Bier of Lincoln: A History of the Germania Club of Chicago, 1865–1986,” Ph.D. diss. (University of Illinois at Chicago, 2007), 116–119.
 Gustav Körner, The Memoirs of Gustave Koerner (Cedar Rapids, Ia., 1909), 2:633.
 “The Courts,” Chicago Tribune, February 24, 1870.
 “The Courts: Poaching on the Premises of a Rival Mining Company.” Chicago Tribune, August 2, 1876.
 Raymond Lohne, “Team of Friends: A New Lincoln Theory and Legacy” Journal of the Illinois State Historical Society, 101.3–4 (2008): 285–314.
 Lohne, “Founded at the Bier of Lincoln,” 116–119.
 “The Germans at La Salle,” Chicago Tribune, August 26, 1872.
 Raymond Lohne, “Lincoln and the German Americans,” unpublished manuscript.
 “Political,” Chicago Tribune, September 14, 1872.
 See for example Mary E. Cookingham, “Bluestockings, Spinsters and Pedagogues: Women College Graduates, 1865-1910,” Population Studies 38.3 (1984): 349–364. For a brief discussion of Camilla Weisbach and Mary Hegeler Carus see also Sandra L. Singer, Adventures Abroad: North American Women at German-Speaking Universities, 1868–1915 (Westport, Conn.: Greenwood Publishing Group, 2003), pp. 126–127, and Marilyn Bailey Ogilvie and Joy Harvey, eds., The Biographical Dictionary of Women in Science: Pioneering Lives from Ancient Times to the Mid-20th Century (New York: Routledge, 2000), p. 235.
 Lisa S. Mastrangelo, “Building a Dinosaur from the Bones: Fred Newton Scott and Women’s Progressive Era Graduate Work at the University of Michigan,” Rhetoric Review 24.4 (2005): 403–420, esp. 404. See also Ruth Bordin, Women at Michigan: The “Dangerous Experiment,” 1870s to the Present (Ann Arbor: University of Michigan Press, 1999).
 Wilfred Byron Shaw, The University of Michigan, 1881–1959 (New York: Harcourt, Brace and Howe, 1920).
 See Box of Mary Hegeler Carus’ Mementos, University of Michigan, Thirty-eighth Annual Commencement, Thursday, June 29, 1882.
 Carus, “Marie Hegeler Carus.”
 Debra Lindsay, “Intimate Inmates: Wives, Households, and Science in Nineteenth-Century America,” Isis 89.4 (1998): 631–652. This lack of recognition would persist throughout her life; for example, “from the 1920s on Paul, Herman, or Edward Carus could always be found in the Chicago Who’s Who… [but] Mary Carus never appears.” Adam McKeown, “The Expansion and Philanthropy of the Matthiessen and Hegeler Business Interests, 1871-1972,” in The Industrial Revolution in the Upper Illinois Valley, ed. Conzen et al., 148.
 Carus, “Marie Hegeler Carus.”
 David Eugene Smith, “Mary Hegeler Carus, 1861–1936,” American Mathematical Monthly 44.5 (1937): 280–283, 281.
 “A Lucrative Monopoly,” Chicago Tribune, Jan. 30, 1888.
 Körner, The Memoirs of Gustave Koerner, 2:633.
 “A Lucrative Monopoly,” Chicago Tribune, Jan. 30, 1888.
 “The La Salle Zinc Works: A Peculiarly European Enterprise – How Its Employees Are Treated,” Chicago Tribune, February 16, 1888.
 On this topic see Marsha Shapiro Rose, “The Legacy of Wealth: Primogeniture among the Rockefellers,” Journal of Family History 27 (April 2002): 172–185.
 See People ex rel. Matthiessen v. Lihme, 269 Ill. 351 (Illinois Supreme Court, October 27, 1915).
 Attorney Affidavit, c. 1915?, in author’s possession.
 See People ex rel. Matthiessen v. Lihme, 269 Ill. 351.
 McKeown, “The Expansion and Philanthropy of the Matthiessen and Hegeler Business Interests,” 120.
 James H. Jolly, U.S. Zinc Industry: A History, Statistics, and Glossary (Baltimore: American Literary Press, 1997), 37–38.
 Jolly, U.S. Zinc Industry, 7–8, 38.
 Constance Meyers, “Paul Carus and the Open Court: The History of a Journal,” Midcontinent American Studies Journal 5 (Fall 1964), p. 59. For biographical information, see also Dictionary of American Biography, 3:548–549; William Ellery Leonard, “Paul Carus,”Dial, 66 (1919), 452–455; William H. Hay, “Paul Carus: A Case-Study of Philosophy on the Frontier,” Journal of the History of Ideas 17 (1956): 498–510; Donald Harvey Meyer. “Paul Carus and the Religion of Science,”American Quarterly 14 (1962): 597–607; James Francis Sheridan, “Paul Carus: A Study of the Thought and Work of the Editor of the Open Court Publishing Company,” Ph.D. diss. (University of Illinois, Urbana, 1957); Harold Henderson, Catalyst for Controversy: Paul Carus of Open Court (Carbondale: Southern Illinois University Press, 1993); and Martin John Verhoeven, “‘Americanising the Buddha’: The World’s Parliament of Religions, Paul Carus, and the Making of Modern Buddhism,” Ph.D. diss. (University of Wisconsin, Madison, 1997).
 William T. Barnes, in private conversation with author, November 4, 2011.
 Mary Hegeler Carus to Edward Carus, July 7, 1909, Hegeler-Carus Family Papers, MSS 32 (Special Collections Research Center, Morris Library, Southern Illinois University at Carbondale, Ill.).
 Mary Hegeler Carus to Edward Carus, Oct. 4, 1909, Hegeler-Carus Family Papers.
 Mary Hegeler Carus to Edward Carus, Nov. 3, 1909 and April 4, 1911, Hegeler-Carus Family Papers.
 Mary Hegeler Carus to Edward Carus, Jan. 7, 1912, Hegeler-Carus Family Papers.
 Henderson,Catalyst for Controversy, 160, 163.
 “Three of Parish Investors Tell Story to Jury,” Chicago Tribune, April 10, 1935.
 Smith, “Mary Hegeler Carus,” 283.
 La Salle Daily Post-Tribune, June 29, 1936.