William Gaertner, a first-generation German immigrant, is remembered as a pioneer of the scientific instrument industry in the United States.
William Gaertner (born October 24, 1864 in Merseburg, Saxony; died December 3, 1948 in Wilmette, IL), a first-generation German immigrant, is remembered as a pioneer of the scientific instrument industry in the United States. Having spent his young adulthood training with some of the best instrument makers in Germany, he immigrated to the United States in 1889. Upon his arrival, he found work with Buff and Berger, a Boston-based firm specializing in surveying equipment. He then moved to Washington, DC, where he worked first for the U.S. Coast and Geodetic Survey Office and then for the Smithsonian Institution. In 1895, he moved to Chicago, where he became part of that city’s rise as a manufacturing metropolis in the early decades of the twentieth century. It was there, in 1896, that he first went into business as a manufacturer of high-grade scientific instruments. By the turn of the century, he had founded Wm. Gaertner & Company. Gaertner established his business at a time when very few scientific instruments were manufactured in the United States. He quickly built up a national reputation as a manufacturer of precision instruments for use in laboratories, universities, and astronomical observatories, and it was not long before his products were being exported worldwide. Gaertner’s company, which operates today under the name Gaertner Scientific Corporation, continues to enjoy an international reputation as a manufacturer and supplier of precision scientific instruments. As one writer explained in a 1944 article in Popular Astronomy, Gaertner’s efforts and accomplishments were “a determining influence and an invaluable contribution to the establishment in this country of a precision scientific instrument industry that is unsurpassed throughout the world.” Gaertner died at the age of eighty-four in 1948, but his legacy continued, for he left his corporation, then valued at $300,000 (approximately $2.72 million in 2010), in a trust to the University of Chicago.
Little is known about William Gaertner’s family background. He was born on October 24, 1864, in Merseburg, Saxony, during a time of rapid industrialization and economic growth. Existing documentation establishes that he was the son of Karl Gaertner and Luise Pippel Gaertner. According to one account, Karl Gaertner was the owner of a paper mill. It appears that Gaertner’s family was able to provide him with an education. As a young boy, he received his early education in public institutions in Berlin.
At the age of sixteen, Gaertner began an apprenticeship with an instrument maker in Halle. He remained there for four years. Afterwards, he moved to Berlin to pursue formal studies in instrument making. He graduated from the Fachschule für Mechaniker (Technical College for Mechanicians), an institution established by the Gesellschaft für Optik and Mechanik (Society for Optics and Mechanics). After completing his education, Gaertner spent approximately five years working for a variety of important firms, including Appel & Company of Göttingen; F.W. Breithaupt & Sons, highly regarded manufacturers of geodetic and astronomical instruments in Cassel; A. Repsold & Sons, the famous makers of astronomical and astrophysical equipment in Hamburg; and Kraft and Son of Vienna, Austria. During these early years, Gaertner also spent brief periods learning from instrument makers in London, Prague, and Rotterdam. The education and training that Gaertner received during his young adulthood in Europe left him well-prepared to start a career in the scientific profession in the United States.
Starting in the post-Napoleonic period, Germans had greater freedom to relocate. After the German states were unified in 1871, industrialization took a firmer hold, and the changes that disrupted both political and economic life encouraged continued emigration. Additionally, dramatic demographic changes, including population growth and urbanization, had a profound effect on German society and ultimately compelled many to seek new places to live. Between 1820 and 1920, the peak period of immigration to the United States, about 5.7 million German-speaking peoples came to the United States. Like Gaertner, many German immigrants were well trained and educated, having already worked as skilled laborers, merchants, or craftsmen in their home country.
Gaertner arrived in New York City on May 20, 1889, at the age of twenty-four. On May 16, 1890, he appeared at the United States District Court for the District of Massachusetts, where he declared his intention to become a naturalized American citizen and vowed to relinquish his allegiance to German Emperor William II. Given his training and experience in the field of scientific instrument manufacturing, it was not difficult for him to find work. Shortly after his arrival, he was hired by Buff and Berger of Boston, manufacturers of surveying, astronomical, and mathematical instruments. The firm had been founded in 1871 by George L. Buff (1837-1923) and Christian Louis Berger (1842-1922), both of whom were German immigrants with educational and professional backgrounds that were extremely similar to Gaertner’s. Like Gaertner, both Buff and Berger had worked for A. Repsold & Sons early in their careers. Since the two were considerably older than Gaertner, and had already immigrated to the United States in the 1860s (Buff in 1864 and Berger in 1868), they would not have overlapped with Gaertner there. But Gaertner’s training at A. Repsold & Sons surely must have stood him in good stead as an applicant for a position in their firm.
After only about a year, Gaertner left Buff and Berger to work for the United States Coast and Geodetic Survey Office in Washington, DC, where he was involved in the construction of invariable pendulums. It would appear that he started his new job at some point in 1890, as the “Statement of the Expenditures of the United States Coast and Geodetic Survey for the Fiscal Year Ending June 30, 1891,” states that one William Gaertner was employed in 1890-91 as an instrument maker for ten months and two days. The same report indicates that Gaertner was also employed as a mechanician for one month and twenty-nine days. For his work as an instrument maker, he was paid a salary of $837 ($20,700 in 2010); for his work as a mechanician, he received $163 ($4,030 in 2010). Working for the federal government in this position meant that Gaertner had to become an American citizen. As a newly arrived immigrant, however, he did not meet all of the necessary requirements for citizenship: immigration law mandated a minimum of five years of residency in the United States before citizenship could be granted. On account of Gaertner’s extensive training, experience, and achievements in the scientific profession, the United States Treasury Department waived his residency requirement. Thus, after only eleven months of living in the United States, Gaertner became a naturalized American citizen.
Gaertner remained with the United States Coast and Geodetic Survey Office for only a short time. According to the “Report of the Instrument Division of the U.S. Coast and Geodetic Survey Office for the Fiscal Year Ending June 30, 1893,” he left the office on April 30 . His departure appears to have created some problems for the office, for the same report notes, “On account of the vacancy among the instrument makers caused by the resignation of Mr. Gaertner on April 30, the services of one man for two months were lost.”
After resigning from his position, Gaertner returned to Germany. Unfortunately, the reason for his trip is impossible to determine. What can be verified, however, is that he eventually reentered the United States on the Aller on September 28, 1893. He landed in New York City, having departed from Bremen. On the ship’s passenger list, he was identified as a “mechanician” by occupation. He registered four pieces of luggage and listed his intended destination as Chicago. By all indications, Gaertner was headed to the World’s Columbian Exposition, also known as the Chicago World’s Fair, which had opened in May of that year and was scheduled to run through the end of October.
At the time, precision instrument manufacturing was still in its infancy in America, and Gaertner’s expertise in the field gave him a tremendous professional advantage. At the World’s Fair, he is said to have met Samuel Pierpont Langley, the secretary of the Smithsonian Institution and the director of the Smithsonian Institute Observatory. Shortly thereafter, Gaertner started working for Langley as an instrument maker in the Smithsonian’s astrophysical laboratory. A distinguished astronomer, physicist, and mathematician, Langley “was recognized as the country’s leading authority in aviation.” Through his work at the Smithsonian, Gaertner came in contact with a number of important scientists and inventors, including Alexander Graham Bell, the inventor of the telephone, and Hiram Stevens Maxim, inventor of the Maxim gun, one of the earliest versions of the machine gun.
After a short tenure at the Smithsonian, Gaertner moved to Chicago in 1895. He arrived in the city at a time of dramatic change. Industrialization had transformed the city during the second half of the nineteenth century, and by the turn of the twentieth century, Chicago had earned an international reputation as a manufacturing metropolis. As a result, the city held an enormous force of attraction for unskilled immigrants, who moved to Chicago in search of factory jobs. At the same time, however, the city was also known as a center for invention and innovation, and as such, it was equally appealing to well-educated immigrants like Gaertner, who recognized the opportunities that Chicago had to offer. It was not long before Gaertner put his German training to optimum use and became an integral part of Chicago’s developing economy.
After arriving in Chicago, Gaertner became affiliated with the Kenwood Physical Observatory. This observatory, located on the South Side of Chicago, was “the gift of William E. Hale of the Hale Elevator company to his son, George E. Hale.” At the time of its opening, the Kenwood Observatory was “better equipped and outfitted than most university observatories of its time.” The inauguration of this observatory attracted many personalities, including Professor Charles Augustus Young, “one of the most distinguished astronomers in the United States,” and Daniel H. Burnham, Director of Works for the World’s Columbian Exposition. The opening of this observatory also represented a great step in Chicago’s quest to put itself on the scientific map. It was there that William Gaertner would establish ties with the influential scientists and astronomers who would later become his customers.
William Hale, who was determined to secure his son a position at the newly established University of Chicago, offered the Kenwood Physical Observatory to the university along with financial support if his son was hired. Hale also asked the university to raise funds for the construction of a larger observatory and to appoint his son director of that new facility. William Rainey Harper, then president of the University of Chicago, accepted the proposal and offered George Hale a faculty position. Although George Hale had already received an employment offer from Harper and had refused it because he wanted to find a position on his own merits, this time he accepted Harper’s offer. As a faculty member at the University of Chicago, Hale was fully committed to the construction of the new observatory. On the morning of October 7, 1892, Hale and Harper visited Charles T. Yerkes at his office at 444 North Clark Street to ask for financial support for a new observatory. Having his name attached to an observatory that would house the world’s largest telescope at that time was incentive enough for Yerkes, who pledged his financial support for the construction of Yerkes Observatory.
Gaertner had constructed instruments for Hale’s use at the Kenwood Observatory, and he continued assisting him at the Yerkes Observatory, where Hale, in accordance with his father’s wishes, served as director. At the Yerkes Observatory, Gaertner worked as one of two mechanicians in the optical laboratory and instrument shop (the other mechanician being the young Austrian immigrant Edmund Kandler). In the instrument shop, the two were supervised by Professor Frank L. O. Wadsworth, an assistant professor at the University of Chicago and an expert in design and engineering. From the very start, the optical laboratory and instrument shop were a source of great pride for the Yerkes Observatory. In the first edition of the Bulletin of Yerkes Observatory, George Hale wrote, “One novel feature in connection with the Observatory will be its instrument shop and optical laboratory, where it is hoped that it will ultimately be possible to construct the greater part of the instruments and laboratory apparatus which will be needed for purposes of investigation.” On-site construction, as Hale explained, was beneficial because it allowed for the instruments to be built under the direct supervision of those who were to use them: “Desirable changes in construction or design which become evident as work progresses can, under these circumstances, be more readily and inexpensively made than when the work is being done at a distance.” This situation, as Hale argued, was advantageous not only to the scientists, but also to the instrument makers, who, in his words, “cannot fail to benefit by the experiments thus undertaken and the types of apparatuses evolved.”
Gaertner’s time at the Kenwood Conservatory and then at the Yerkes Observatory proved extremely profitable. As he continued to develop his skills, his talents were recognized by, among others, Professor Albert Abraham Michelson, who headed the Department of Physics at the University of Chicago. Michelson, who was born in Strelno, Prussia, but immigrated to the United States as an infant, would later become the first American recipient of a Nobel Prize in a scientific field. With Michelson’s encouragement, Gaertner decided to start a business with Kandler, who had once been the junior partner of German instrument manufacturer Roman Seeling. Although Gaertner left the staff of the Yerkes Observatory, he continued to supply Hale and the scientists there with instruments that he manufactured in his shop. Over the years, the observatory would be one of his most important customers.
In 1896, the same year in which he received his final citizenship papers, Gaertner entered into a partnership with Kandler, and the two opened a small shop, Kandler & Gaertner, on Dearborn Street near the University of Chicago. There, as experienced mechanicians, they manufactured astronomical instruments and other accessories. Kandler & Gaertner opened at a time when very few scientific instruments were manufactured in this country, and the scientific community welcomed the new venture. In 1896, Astrophysical Journal announced, “Having had the opportunity to become familiar with their work, we gladly recommend Messrs. Kandler & Gaertner to those who desire to have instruments constructed or repaired.” The article continued, “On account of the difficulty of getting bolometers made elsewhere, it is worthwhile to mention that Mr. Gaertner is very skilful in constructing them.” Gaertner’s expertise in the manufacturing of bolometers most likely resulted from his work at the Smithsonian with Professor Langley, who was the inventor of such devices. Gaertner and his partner stood apart in the instrument manufacturing business. It helped that, from the beginning, as a German-trained instrument maker, Gaertner was associated with excellent craftsmanship.
One of Gaertner’s first orders came from the Armour Institute of Technology, the predecessor to today’s Illinois Institute of Technology. Shortly thereafter, the University of Wisconsin placed an order for an astrophotometer. Gaertner crafted this instrument, used to measure the brightness of stars, with such precision and craftsmanship that it attracted the attention of other scientists, including German-born physiologist Jacques Loeb and physicist Samuel Wesley Stratton, both of the University of Chicago. Loeb went on to commission many physiological and physical instruments from Gaertner, and Stratton, who eventually became director of the newly formed U.S. Bureau of Standards and then president of the Massachusetts Institute of Technology, referred many customers to him. Gaertner also received commissions from Michelson, for whom he designed an interferometer.
Gaertner’s partnership with Kandler ended after only a year. By 1897, Kandler was running the Dearborn Street shop on his own, and Gaertner had a new partner, C.E. Regennas, an instrument maker who had spent seven years working for the United States Coast and Geodetic Survey, for whom Gaertner himself had briefly worked. It appears that the two became acquainted there, as their periods of service overlapped. Gaertner & Regennas set up shop at 152 Fifty-Sixth Street in Chicago. According to an advertisement in The Journal of Applied Microscopy (Volume 1, 1898), they specialized in astronomical, physical, physiological instruments, including refracting and reflecting telescopes and other universal scientific instruments. The advertisement ended with the following statement, “CAREFUL ATTENTION paid to the design and construction of special apparatus for RESEARCH WORK.”
Like his venture with Kandler, Gaertner’s partnership with Regennas appears to have been short-lived. In 1898, Gaertner was listed in The Lakeside Directory of Chicago as the sole proprietor of “William Gaertner & Co., scientific instrument makers,” which was located at 152 Fifty-Sixth Street, the former site of Gaertner & Regennas. By 1899, William Gaertner & Co. had moved to 5347 Lake Avenue.
By that time, Gaertner had also received a major contract from the Smithsonian for the construction of a scientific camera capable of capturing images in a fraction of a second. On March 19, 1899, The New York Times reported: “the finest gun camera ever built is being constructed in Chicago by William Gaertner.” As the paper explained, the construction of this camera was greatly anticipated as “it shall be capable of making a successful exposure in one six-hundredth of a second [ . . . ] the gun camera for the Smithsonian Institution is by far the best telephotographic instrument ever attempted, and surpasses all others of its kind.”
Gaertner’s successful completion of various commissions had a ripple effect within the scientific community, and his customer base grew by way of personal recommendations. For example, in response to readers’ requests for advice on spectroscopes for amateur enthusiasts, David E. Hadden praised the “workmanship, reasonable price, and performance” of a Gaertner manufactured instrument in a 1904 article in Popular Astronomy.  He provided his readers with a detailed description accompanied by various pictures. He was sure his assessment of Gaertner’s products would be of interest to many.
The precise handicraft and inventive designs that brought him such success within the United States also helped him establish an international reputation and sparked a demand for his products abroad. Thus, after only a couple of years in operation, he began exporting precision instruments outside the United States – a remarkable achievement, especially given the fact that only a few years earlier such instruments had to be imported from European manufacturers.
The year 1907 brought Gaertner more national attention as the country prepared for the Lowell Mars Expedition to South America. As part of this venture, a team of scientists would travel to the Andes to await the appearance of Mars at its zenith. Their goal of photographing the “canals and polar caps of the planet Mars” would be achieved with a Gaertner instrument.  According to the New York Times, what made this camera astonishing was its ability to take numerous exposures on one plate and its concave lens, which enlarged the image on the plate instead of diminishing it, as did the lenses of an ordinary camera.
The expedition, which was the subject of widespread press attention, undoubtedly provided a boost to Gaertner’s already flourishing business. His company now took up three storefronts on Lake Avenue (numbers 5345-5349), and his 1908 catalog, Astronomical Instruments and Accessories, listed more than twenty products that were available for order. The thirty-page catalog explained that most of the instruments were not kept in stock, but rather made to order. It also made clear that Gaertner had carved out a niche designing custom-made instruments for researchers, laboratories, and universities:
As a rule, every astronomer is interested in some special line of research, which for a successful investigation requires a special adaptation of the instrument he proposes to use, and in such cases we are confident we can fill the requirements [ . . . ] We are in [a] position to undertake the design of special apparatus and can furnish sketches and estimates in accordance with the suggestions of the customer [ . . . ].
A notice printed on the first page of the catalog laid out Gaertner’s customer satisfaction guarantee and explained that any piece that did not “come up to the most exacting requirements” would be promptly replaced. The guarantee attests to value that Gaertner placed on customer satisfaction, which was obviously an essential part of his business. “It is and has been the aim of our firm,” the catalog read, “to produce apparatus of the highest grade and the constant growth of our business is a mute but eloquent testimonial that our efforts have been appreciated by our customers.” 
By the 1910s, Gaertner’s talents and achievements had attracted the attention of the International Geodetic Association. The United States joined this organization after the imperial government of Germany issued an invitation, which was, in turn, accepted by Congress in 1889. With its aim of accurately measuring the earth, the International Geodetic Association established two observatories in the United States, one in Maryland and the other in California. The International Geodetic Association contracted with William Gaertner and his firm to manufacture a photographic zenith telescope according to the specifications of American astronomer and physicist Dr. Frank E. Ross. The purpose of this instrument was to take accurate latitudinal and longitudinal measurements. The successful construction of this instrument represented a major feat: “European astronomers of that period were skeptical as to its feasibility and success, but Mr. Gaertner undertook the design and construction of this delicate piece of work and it proved entirely satisfactory.” International orders for astronomical equipment poured in as a result of Gaertner’s success with the photographic zenith telescope.
Gaertner also received a large number of requests for astronomical comparators, whose construction required the production of precision lead screws for scientific instruments. Lead screws were an essential component, since they translated turning motion into the linear motion needed for machine tools. This being the case, Gaertner embarked on a project that had appealed to him since the beginning of his career: he decided to produce these lead screws himself. Manufacturing them was risky, since they need to be extremely precise: “Making precision screws is one of the most difficult operations connected with the production of fine tools, instruments, or machines for which such screws may be required.” Because of the level of precision that was called for, many producers failed in their attempts to manufacture lead screws. “In making parts of scientific instruments, the case is very different, because here errors which would be quite insignificant in any commercial work may be multiplied as a result of the condition under which the instruments are used.” To successfully manufacture these screws for astronomical use, Gaertner took a number of precautions to ensure precision. He used fine grained steel, carefully inspected each screw after cutting it, and allowed the screws to set for months. After the screws rested and assumed their final form, Gaertner inspected them again and made any final cuts. Using a lathe manufactured in Germany by W. von Pittler of Leipzig, Gaertner used the techniques he had learned from some of Germany’s best-known instrument makers and, in the end, produced extremely accurate lead screws.
World War I presented more opportunities for Gaertner’s company as U.S. government agencies sought out his services. At the same time, however, the war also posed some problems for his business. In 1915, for example, civil engineer John Darling secured permission to build a public observatory in Duluth, Minnesota. He agreed to bear all the related expenses and asked Gaertner to manufacture an eight-inch lens for the observatory’s telescope. Unfortunately, Gaertner was not able to procure the materials needed to fill this order. The war limited the glass supply, and, as a result, he did not have enough glass to produce the lens. Darling ended up purchasing a nine-inch lens from the John A. Brashear Co. of Pittsburg.
Despite the war’s effect of the availability of materials, and despite the anti-German sentiment of the time, Gaertner’s list of customers and commissions continued to grow. As the demand for Gaertner’s instruments increased, so did the needs of the company. In 1923, he purchased the optical shop of his longtime friend O.L. Petitididier. It was then that Wm. Gaertner & Co. was incorporated, renamed the Gaertner Scientific Corporation, and relocated to a new site at 1201Wrightwood Avenue, Chicago. With larger facilities, Gaertner diversified his product line and manufactured a number of additional instruments, including spectrographs, spectrometers, and diverse optical instruments. Today, the former manufacturing plant on Wrightwood Avenue still bears Gaertner’s name.
Gaertner’s designs and contributions to science garnered much recognition from his peers. In 1924, for example, he received the Howard N. Potts Gold Medal from the Franklin Institute in Philadelphia. Recipients were selected by a committee of sixty members of the institute, and the medal was granted annually to one individual “for distinguished work in science or the arts; important development of previous basic discoveries; inventions or products of superior excellence or utilizing important principles.” Gaertner was awarded the medal for developing a piece of surgical apparatus: an injector for dosing serums and for use in blood transfusions.
In 1933, amidst a national depression, Chicago held the Century of Progress International Exposition to celebrate the city’s centennial. The fair, which drew inspiration from futuristic designs and technological advancements, opened on May 27, 1933, and ran until November 12, 1933. It opened again for a second year on May 26, 1934, and finally closed on October 31, 1934. With “Science Finds, Industry Applies, Man Adapts” as its motto, the fair sought to highlight the progress that had been made in science. This exposition was held to “attempt to demonstrate to an international audience the nature and significance of scientific discoveries, the methods of achieving them, and the changes which their application has wrought in industry and in living conditions.” Celebrated on Chicago’s lakeshore, the exposition attracted an astounding thirty-nine million visitors to visionary exhibits, which included the Chrysler Building, the Sky Ride, and a 200-foot-high thermometer.
Gaertner’s innovative designs were a perfect fit for the fair’s various exhibits on aeronautical instruments. The Gaertner Scientific Corporation agreed to build a number of exhibits for the exposition’s Hall of Science and requested that Century of Progress Bonds be used as the form of payment, under the condition that these bonds would be accepted as payment for the space the company required. “Bomb sights, gun cameras, oxygen breathing equipment and inclinometers will be included in an exhibit of scientific instruments by the Gaertner Scientific Corporation, of Chicago,” announced Progress,the fair’s official publication.
Among many apparatuses, Gaertner exhibited a “pantograph of the type used in the U.S. Hydrographic Office, U.S. Geological Survey, U.S. Coast Guard and Geodetic Survey, Great Lakes Survey in Detroit, and others.” This device weighed approximately 2,500 pounds, measured over eight feet, and stood over thirty inches from the ground. The fair’s organizers also wanted to exhibit a Gaertner-made quartz spectrograph then valued at $350 (almost $6,000 in 2010). This spectrograph was to be used for the balloon stratosphere flight of Major Chester L. Fordney of the United States Marines and Lieutenant Settle of the United States Navy.
By October 1933, approximately four months after the fair opened, Gaertner petitioned the exposition’s Director of Exhibits, Mr. C.W. Fitch, for permission to remove a Gaertner pantographer from the Mathematics Division in the Science Hall. According to a letter from Gaertner to Fitch, the device had been purchased by the U.S. Lake Survey, located in Detroit, and this institution was awaiting its arrival. Purchases of this sort by U.S. government agencies were common. A few years earlier, the Hydrographic Office had purchased five. In fact, the 1929 Annual Report of the Hydrographic Office described these pantographers as “excellent instruments.” With a U.S. agency awaiting the arrival of the device, the Exhibits Department released the instrument.
By World War II, the United States had a well-established precision scientific instruments industry. At that time, universities, laboratories, and research institutions throughout the nation could obtain high-grade scientific equipment and precision tools manufactured in the United States. Decades earlier, however, such apparatuses had to be imported from Europe, which had long dominated this market. “Prior to 1914, practically all instruments of precision were imported and when our government declared war in 1917, it was found that there were not enough instrument makers and manufacturers to provide adequate supplies of precision instruments [ . . . ].” As an immigrant to the United States, Gaertner put his European training to use to manufacture products that were in high demand in a place where there was initially little competition. While his skills obviously played a crucial role in the development of his business, he was also aided by U.S. government regulations – during the interwar years, for example, the federal government imposed a tariff on scientific instruments and optical devices to facilitate the development of an American industry.
Newspaper articles often referred to Gaertner as a wealthy instrument maker. Outside of his work, Gaertner belonged to the American Astronomical Society, founded in 1899 for professional astronomers. As a member of the Chicago elite, he was also a member of the Chicago Association of Commerce, an organization founded in 1904 to represent the interests of Chicago business owners and to create a stronger city economy. Gaertner also belonged to the Press Club of Chicago, whose membership included entrepreneurs and professionals who maintained busy social lives.
As founder and president of a prosperous business, Gaertner could afford a comfortable life. He lived in Chicago’s Hyde Park neighborhood, which was home to the University of Chicago and the site of the 1893 World’s Fair. Gaertner’s fortunes allowed him to travel around the world and to take cruises to exotic places like South America. When he was not occupied by business matters or traveling abroad, Gaertner enjoyed riding horses in the city’s Washington and Jackson Parks. In fact, he owned fifteen stallions. He shared his love for horses with a woman who would later become his wife, Belle Oberbeck, a cabaret singer whose stage name was Belle Brown.
By the time he reached his early fifties, Gaertner, as a successful, unmarried entrepreneur, was considered “a matrimonial prize.” “Any woman could see that this gentleman was a pearl among men, from a wife’s point of view [ . . . ].” Additionally, there were two qualities that made him even more attractive: he was rich and generous. According to one press account, William Gaertner and Belle Oberbeck met at a loop cabaret, where Belle was a dancer and William went “for diversion from his business of manufacturing scientific instruments.” Apparently, after being abandoned by her first husband, Mr. Overbeck, Belle befriended Gaertner, and their mutual interest in equestrianism formed the basis of a romance that ultimately led to the altar. The two were married in June 1917 in Crown Point, Indiana. At the time, William was fifty-three, and Belle was thirty-one. After their wedding, the couple went to West Baden, Indiana, for a five-day honeymoon. Belle changed her name to Belva, perhaps to signify her new beginning as the wife of a wealthy manufacturer. The marriage soon soured, however. Gaertner had no interest in the nightlife that his wife constantly sought out, and his age, tastes, and business obligations prevented him from accompanying her on her regular nightclub visits. He saw no solution other than divorce. On August 3, 1917, after only few months of marriage, Gaertner filed a bill to petition for a divorce. In the process, Mr. Gaertner’s lawyer discovered that the couple’s union was actually illegal and thus subject to annulment. It appeared that Belva, who had divorced Mr. Oberbeck on April 27, 1917, had violated an Illinois statute mandating a one-year waiting period between a divorce and a remarriage. Gaertner’s petition was unique. No such case had ever been heard by an Illinois court. While a decision was being made on their case, Belva requested weekly alimony. She asked for $50 in temporary weekly alimony (approximately $850 in 2010). Gaertner and his lawyers protested, arguing that if the marriage was in violation of Illinois law then it would be annulled and alimony would not come into question. On September 25, 1917, Judge Joseph Fitch denied Mrs. Gaertner’s request for alimony. After a short time, William and Belva were divorced.
But Gaertner’s relationship with Belva did not end with the dissolution of their first marriage in 1917. They continued to see each other and headed back to the altar that very same year. Their second marriage lasted about three years. During that time, the problems continued. Gaertner claimed that his wife was unfaithful and that he had found her with another man. Consequently, he sought a divorce. This time, the marriage was deemed legal, and Mrs. Gaertner was entitled to marital property. To ensure that she would cooperate with the divorce, William Gaertner offered Belva Gaertner $3,000 (over $30,000 in 2010). She accepted the money, along with their home furnishings. By 1920, Mr. and Mrs. Gaertner were once again divorced. This, however, did not signal the end of their legal battles.
By 1924, the Gaertner name was all over the newspapers again; this time, it was not on account of William’s successful business endeavors or the couple’s sensational divorce, but rather because Belva Gaertner had been accused of murdering auto salesman Walter Law. After Law was found dead, Gaertner was incarcerated on the night of March 12, 1924, and held without bail. According to most accounts, Belva Gaertner and Law, a married man and a father of one, had a romantic relationship, which sometimes turned violent. On the night in question, Mrs. Gaertner and Mr. Law had visited the Gingham Café and had left drunk. The next morning, Mr. Law’s body was found in Belva Gaertner’s car, a gift from her former husband. He had been shot in the head, and the gun was nearby. The police found Belva Gaertner in her apartment in a frantic state; her clothes were covered in blood. She claimed not to be able to remember anything that had occurred the night before because she had been too drunk. William Gaertner hired three of Chicago’s best attorneys to represent his former wife.
Over the next couple of months, the prosecution tried to portray Belva as a violent, jealous woman capable of killing her lover. Belva insisted on her innocence, arguing that she had not killed Walter and had never threatened his life. Moreover, she added that Walter would have left his wife, had it not been for their son. As Belva stood trial, Gaertner supported her. In fact, he hoped for reconciliation as soon as the trial ended. After six and a half hours of deliberations, the jury acquitted Belva Gaertner on the grounds that there was insufficient evidence to convict her of the murder of Walter Law. After the final verdict was read, Belva announced that she planned to marry Gaertner again and to head to Europe to forget the ordeal.
After her acquittal, Belva renewed her romantic relationship with William. “Belva Gaertner Marries Former Husband 3D Time,” announced the Chicago Daily Tribune on May 3, 1925. Belva and William Gaertner were once again husband and wife. Like their previous two attempts at marriage, this one failed as well, and the couple was back in court almost immediately. Gaertner, by now sixty-one years old, filed for divorce. He claimed that shortly after they remarried, Belva commenced drinking heavily, was unfaithful, and even became violent towards him. By August 1926, Gaertner was once again embroiled in ugly divorce proceedings. Belva countersued and argued that, other than dancing, she had done none of the things that her husband accused her of. After a number of legal battles, the couple reconciled, and this time their marriage lasted.
Gaertner and his wife did not have any children. In 1937, the Gaertners were in the news once again; this time in connection with the custody battle for nine-year-old Elaine Harnett, the granddaughter of William Gaertner’s sister-in-law, Mrs. Mae Kirkpatrick. William and Belva Gaertner were very fond of Elaine, who had been in Kirkpatrick’s care for six years. When Elaine’s mother, Veronica Harnett, sought to regain custody of her daughter, Mrs. Kirkpatrick asked the Gaertners to intervene. William and Belva Gaertner had hoped to raise and educate Elaine. They offered to set up a $500,000 trust fund (approximately $7,590,000 in 2010) for Elaine, in the hopes of convincing her to stay with them. Elaine chose to return with her mother and three-year old brother.
Gaertner’s married years proved very trying. With his legal affairs becoming more complicated and his business responsibilities more demanding, Gaertner started to rely more on others within his company organization. Documents from this time show that Gaertner’s sales manager and leading physicist took a more active role in the organization. Gaertner spent the last twelve years of his life living inWilmette, Illinois. He died on December 3, 1948. His death was caused by a long struggle with edema. He had suffered from coronary sclerosis for two years prior to his death. Gaertner is buried at Mt. Greenwood Cemetery, in Chicago, Illinois. Belva Gaertner spent her later years living in Pasadena, California, where she died in 1965.
William Gaertner is among those German immigrants who greatly influenced the development of this nation. In an article published in 1944, four years before Gaertner’s death, his career was summarized as follows: “Mr. Gaertner was probably the first in the United States to establish an export business in scientific instruments and has constantly striven to promote the establishment in this country of a diversified precision instrument industry able to compete successfully with the best European products.” From the very start, Gaertner’s German background played an important role in the development of his career as an instrument maker. He arrived in the United States with skills and expertise that he had acquired through his training at the Fachschule für Mechaniker (Technical College for Mechanicians) and through various apprenticeships with some of Germany’s leading instrument makers. His first job in the United States was with Buff and Berger, a firm founded by two German immigrants, both of whom were once associated with A. Repsold & Sons of Hamburg, for whom Gaernter had also worked. Both before and after the founding of his own firm, Wm. Gaertner & Company, Gaertner collaborated with many renowned German-born scientists, including Albert Abraham Michelson and Jacques Loeb. The tradition of quality and handcraftsmanship that he brought with him from Europe was an important part of his success in America, and evidence of Gaertner’s ongoing adherence to this tradition could be found in the satisfaction of his loyal customer base.
Throughout his career, Gaertner displayed the utmost professionalism and decorum in matters both professional and private. Press accounts of the Gaertners’ marital tribulations and stories about Belva Gaertner’s murder trial tended to portray Gaertner as a kindly, patient gentleman. His kindness, concern, and loyalty appear to have extended to his employees as well. As president of the Gaertner Scientific Corporation, Gaertner made sure that his plant was well equipped, that his workers were happy, and that the working environment was conductive to health and productivity. Gaertner’s concern for his employees became even more evident after his death, when it was revealed that he had placed most of his fortune in a living trust with Northern Trust Company as its executor. In an arrangement that the New York Times described as an “unusual trust,” Gaertner left his “$300,000 business to the University of Chicago with the provision that the university run the business for twenty-one years to insure jobs for veteran employees.” His will also provided for his widow, Belva Eleanora Gaertner, to whom he left an estate valued at $25,000 (approximately $226,000 in 2010).
 R.T. O’Connor, “William Gaertner, 1864-1948,” Popular Astronomy 57 (1949): 65
 Lyman W. Higgins, “The Work of William Gaertner,” Popular Astronomy 52 (1944): 442-45.
 All current values (in 2010 USD) are based on Samuel H. Williamson, “Seven Ways to Compute the Relative Value of a U.S. Dollar Amount, 1774 to present,” MeasuringWorth, 2011, using the Consumer Price Index.
 “Leaves Firm in a Trust to Aid Workers,” Chicago Daily Tribune, December 15, 1948.
 Glenn A. Bishop and Paul T. Gilbert, Chicago’s Accomplishments and Leaders (Chicago, IL: Bishop
Publishing Company, 1932), 213.
 Brian Carr, “A 1908 Brass Refractor,” Journal of the Royal Astronomical Society of Canada Newsletter, vol. 77 (1983): L7.
 Bishop and Gilbert, Chicago’s Accomplishments, 213.
 O’Connor, “William Gaertner, 1864-1948,” 65
 “A New Firm of Instrument Makers,” Astrophysical Journal 4 (1896): 84.
 O’Connor, “William Gaertner, 1864-1948,” 65; Higgins, “The Work of William Gaertner,” 442.
 O’Connor, “William Gaertner, 1864-1948,” 65.
 Edward Purcell, Immigration (Phoenix, AZ: The Oryx Press, 1995), 29-30.
 On George L. Buff, see “Department of the History of Science, Harvard University. People: George L. Buff,” (accessed on December 11, 2012); on Christian L. Berger, see: J.P. Whitelaw, “The Early History of Berger Instruments,” Professional Surveyor Magazine, January/February 1997, (accessed on December 11, 2012).
 Nor did Buff and Berger overlap with each other there; it would appear that they met in England, where both worked for a time for Cooke and Sons. See Whitelaw, “The Early History of Berger Instruments.”
 O’Connor, “William Gaertner, 1864-1948,” 65.
 52nd Congress, 1st Session, House of Representatives, Ex. Doc. No. 151, Expenditures Coast and Geodetic Survey, 1891. Letter from the Secretary of the Treasury, transmitting a statement of expenditures on account of the Coast and Geodetic Survey for the fiscal year ending June 30, 1891 (Treasury Department, Office of the Secretary: Washington, DC, March 1, 1892), p. 5.
 Bishop and Gilbert, Chicago’s Accomplishments, 213.
 Report of the Superintendent of the U.S. Coast and Geodetic Survey Showing the Progress of the Work during the Fiscal Year Ending with June, 1893. In Two Parts. Part I (Washington, DC: Government Printing Office, 1894), p. 119.
 Passenger Lists of Vessels Arriving at New York, New York, 1820-1897; (National Archives Microfilm Publication M237, 675 rolls); Records of the U.S. Customs Service, Record Group 36; National Archives, Washington, D.C.; Source Citation: Year:1893;Arrival;Microfilm Serial:M237;Microfilm Roll:619;Line:21; from Ancestry.com. New York, Passenger Lists, 1820-1957 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2010.
 O’Connor, “William Gaertner, 1864-1948,” 65.
 Carr, “A 1908 Brass Refractor,” L7.
 O’Connor, “William Gaertner, 1864-1948,” 65.
 Robert M. Kane, Air Transportation: 1903-2003 (Dubuque, IA: Kendall/Hunt Publishing Company, 2003), 56.
 O’Connor, “William Gaertner, 1864-1948,” 65-66; Higgins, “The Work of William Gaertner,” 442.
 See Sarah S. Marcus, “Turn-of-the-Century Industrialization and International Markets,” Encyclopedia of Chicago (accessed on December 12, 2012), and Louis P. Cain, “Innovation, Invention, and Chicago Business,” Encyclopedia of Chicago, (accessed on December 12, 2012).
 Higgins, “The Work of William Gaertner,” 442.
 “Astronomy in Kenwood,” The Chicago Daily Tribune, June 16, 1891.
 Donald E. Osterbrock, Yerkes Observatory, 1892-1950: The Birth, Near Death, and Resurrection of a Scientific Research Institution (Chicago, IL: The University of Chicago Press, 1997), 6.
 “Astronomy in Kenwood.”
 Osterbrock, Yerkes Observatory, 1892-1950, 8.
 Ibid, 2.
 See George E. Hale, The Organization of the Yerkes Observatory, Bulletin No. 1, Yerkes Observatory, University of Chicago (1896): 1.
 Ibid, 28.
 Ibid, 3.
 Osterbrock, Yerkes Observatory, 1892-1950, 8. See also, The Lakeside Annual Directory of the City of Chicago, 1896 (Chicago, IL: The Chicago Directory Company, 1896), p. 711, p. 1032.
 “A New Firm of Instrument Makers,” 84
 Higgins, “The Work of William Gaertner,” 442.
 O’Connor, “William Gaertner, 1864-1948,” 66.
The Lakeside Annual Directory of the City of Chicago, 1897 (Chicago, IL: The Chicago Directory Company, 1897), p. 1092.
 William W. Payne and H.C. Wilson, eds., “General Notes,” Popular Astronomy 5 (1897-98): 114.
 Report of the Superintendent of the U.S. Coast and Geodetic Survey Showing the Progress of the Work during the Fiscal Year Ending with June, 1893, p. 119.
The Lakeside Annual Directory of the City of Chicago, 1897 (Chicago, IL: The Chicago Directory Company, 1897), p. 750.
The Lakeside Annual Directory of the City of Chicago, 1898 (Chicago, IL: The Chicago Directory Company, 1898), p. 660.
The Lakeside Annual Directory of the City of Chicago, 1899 (Chicago, IL: The Chicago Directory Company, 1899), p. 673.
 “A Marvelous New Camera,” New York Times, March 19, 1899.
 David E. Hadden, “Spectroscope for Small Telescopes,” Popular Astronomy 12 (1904): 252.
 O’Connor, “William Gaertner, 1864-1948,” 66.
 “New Camera to Take Mars,” New York Times, May 9, 1907.
 William Gaertner & Co., Catalog A. 1908. Astronomical Instruments and Accessories. [Chicago, IL: William Gaertner & Co., 1908], n.p.
 United States Government, Reports of the Department of Commerce: Reports of the Secretary of Commerce and Reports of Bureaus (Washington, DC: Government Printing Office, 1915), 168.
 O’Connor, “William Gaertner, 1864-1948,” 66.
 Higgins, “The Work of William Gaernter,” 443.
 Franklin Day Jones, Thread-Cutting Methods (New York, NY: The Industrial Press, 1918), 322.
 Edward K. Hammond, “Making Precision Screws for Scientific Instruments,” Machinery 23 (1917): 849.
 Ibid., 850.
 Higgins, “The Work of William Gaertner,” 444.
 The Franklin Institute of the State of Pennsylvania, Yearbook (Philadelphia, PA: The Franklin Institute, 1919), 42.
 “Here and There,” Scientific American (April 1924): 231.
 Dominic A Pacyga, Chicago: A Biography (Chicago, IL: The University of Chicago Press, 2009), 264.
 Wayne Lundquist, Len the Pilot (United States of America: Xlibris Corporation, 2011), 55.
 Albert A. Hoffman, Jr., Some Historical Stories of Chicago (United States of America: Xlibris Corporation, 2011), 194.
 Robert G. Spinney, The City of Big Shoulders: A History of Chicago (DeKalb, IL: Northern Illinois University Press, 2000), 188.
 A.L. Klein, Sales Manager to Mr. F.C. Boggs, June 9, 1933, box 201 “Century of Progress Records, series I”, University of Illinois at Chicago Daley Library Special Collections and University Archives, Chicago.
 William Gaertner to Dr. Henry Crew, October 28, 1932, box 201 “Century of Progress Records, series I”, University of Illinois at Chicago Daley Library Special Collections and University Archives, Chicago.
 “Gaertner Plans Display of Line,” Progress, January 13, 1932.
 G.F. Shepherd to Dr. Crew, February 7, 1933, box 201 “Century of Progress Records, series I”, University of Illinois at Chicago Daley Library Special Collections and University Archives, Chicago.
 William Gaertner to Mr. C. W. Fitch, Director of Exhibits, October 26, 1933, box 201 “Century of Progress Records, series I”, University of Illinois at Chicago Daley Library Special Collections and University Archives, Chicago.
 Hydrographic Office, Annual Report of the Hydrographic Office for the Fiscal Year 1929: Appendix No. 1 to the Annual Report of the Chief of the Bureau of Investigation, 1929, (Washington, DC: Government Printing Office, 1929), 6.
 American Association for the Advancement of Science, “Association of Scientific Apparatus Makers of the United States of America,” Science 51 (1920): 588.
 Philip Hampson, “War Develops U.S. Output of Precision Aids: Market for Foreign Tolls Replaced,” Chicago Daily News, November 10, 1944.
 “Husband Sues Belva Gaertner, Freed in Murder,” Chicago Daily Tribune, August 1, 1926.
 Bishop and Gilbert, Chicago’s Accomplishments, 213
 “Chicagoans on Cruises around South America,” Chicago Daily Tribune, February 7, 1937.
 “Riding to a Fall: Bridle Path Leads to Altar and Thence to Court, Where Counter Suits Will Test Remarriage Law,” Chicago Daily Tribune, September 16, 1917.
 “The Matrimonial Worm that Turned at Last,” San Antonio Light, January 9, 1927.
 “Sued Wife Keeps Detective Guard,” Waterloo Evening Courier (Waterloo, Iowa), April 10, 1920, 8.
 “Riding to a Fall.”
 According to Douglas Perry, author of The Girls of Murder City (New York, NY: Viking, 2010), Belva Gaertner was born on September 15, 1885. He lists his source as the Illinois Soldiers’ and Sailors’ Orphans’ Home Records, 1900 (255.004-008), Illinois State Archives. See Perry, note 41, p. 274.
 “Belle Gaertner, Once A Dancer, Denied Alimony,” Chicago Daily Tribune, September 25, 1917.
 “Hold Divorcee as Slayer of Auto Salesman,” Chicago Daily Tribune, March 13, 1924.
 “Other Woman’s Gems Shine as Widow Sneers,” Chicago Daily Tribune, 13, 1924.
 Maurice Watkins, “Jury Finds Mrs. Gaertner Not Guilty,” Chicago Daily Tribune, June 6, 1924.
 “Belva Gaertner Marries Former Husband 3D Time,” Chicago Daily Tribune, May 3, 1925.
 “Belva Gaertner Will Fight her Rich Husband’s Suit,” Chicago Daily News, August 2, 1926.
 Ursula Petrie, “How One Little Girl Decided a ‘Vanderlitl’ Case,” Billings Gazette, August 22, 1937; “Child Prefers Mother to Promise of $500,000, Oshkosh Daily Northwestern (Oshkosh, WI), July 22, 1937, 10; “Girl, 9, Prefers Mother, Pup, to Promise of Half Million,” Mansfield News Journal (Mansfield, OH), July 27, 1937, 18.
 Higgins, “The Work,” 444.
 See, for example, “Riding to a Fall” and “The Matrimonial Worm that Turned at Last.”
 Higgins, “The Work of William Gaertner,” 445.
 “Business Left to Chicago U,” The New York Times, December 15, 1948.