Black Inventor -

Thomas Jennings

Thomas Jennings stands in history as a noteworthy figure for being the first Black person to ever receive a patent, but his life should serve as an example of what was, and what could have been, for Black people in the earliest years of the United States.

Thomas Jennings was born in 1791 and worked in a number of jobs before focusing on what would become his chosen career… as a tailor. Jennings’ skills were so admired that people near and far came to him to alter or custom-tailor items of clothing for them. Eventually, Jennings reputation grew such that he was able to open his own store on Church street which grew into one of the largest clothing stores in New York City.

Jennings, of course, found that many of his customers were dismayed when their clothing became soiled, and because of the material used, were unable to use conventional means to clean them. Conventional methods would often ruin the fabric, leaving the person to either continue wearing the items in their soiled condition or to simply discard them. While this would have provided a boon to his business through increased sales, Jennings also hated to see the items, which he worked so hard to create, thrown away. He thus set out experimenting with different solutions and cleaning agents, testing them on various fabrics until he found the right combination to effectively treat and clean them. He called his method “dry-scouring” and it is the process that we now refer to as dry-cleaning.

In 1820, Jennings applied for a patent for his dry-scouring process. In light of the times, he was fortunate that he was a free man, born in the United States, and thus an American citizen. Under the United States patent laws of 1793 (and later, as revised in 1836) a person must sign an oath or declaration stating that they were a citizen of the United States. While there were, apparently, provisions through which a slave could enjoy patent protection, the ability of a slave to seek out, receive and defend a patent was unlikely. Later, in 1958, the patent office changed the laws, stating that since slaves were not citizens, they could not hold a patent. Furthermore, the court (in the famous case Oscar Stuart vs. Ned case) said that the slave owner, not being the true inventor could not apply for a patent either. In true irony, when many of the southern states seceded from the Union to form the Confederate States of America, CSA President Jefferson Davis signed into law legislation permitting slaves to hold patents. For Thomas Jennings, none of this mattered because as a free man, not only was he able to receive a patent in 1821, but he was also able to utilize it for his financial gain. In fact, he made a fortune.

What makes Jennings noteworthy is not just that he was an entrepreneur or that he received a patent, or even the fact that he became very wealthy. What is noteworthy is that he took a vast amount of the proceeds of his business and poured it into abolitionist activities throughout the Northeast. In fact, in 1831, he became the assistant secretary for the First Annual Convention of the People of Color in Philadelphia, Pennsylvania. He passed this sense of self-worth to his daughter Elizabeth, who was forced off of a public bus in New York City which she riding to go to church. Because of her father’s prominence and wealth, she was able to obtain the best legal representation and hired the law firm of Culver, Parker, and Arthur to sue the bus company and was represented in court by a young attorney named Chester Arthur, who would go on to become the 21st President of the United States. Ms. Jennings would ultimately win her case in front of the Brooklyn Circuit Court in 1855.

Thomas Jennings died in 1859 and will go down in history as the first Black person to obtain a patent, but he should rather be seen as an example of a citizen who made the best of his life and sought to use his good fortune to make life better for those around him.


  • The Inventive Spirit of African Americans (Patricia Carter Sluby).

Thomas Mensah

Thomas Mensah - blackinventor.comThomas Mensah was born in Kumasi, Ghana in 1950. His father, J.K. Mensah, was a businessman who shipped cocoa products to chocolate manufacturers in France. Thomas was an exceptionally bright child, learning to read newspapers at an early age and becoming fluent in French. As a child, he often conversed in French with his father’s business associates. He went on to twice win the National Competition in France in 1968 and 1970.

Thomas received his early education at the exclusive Adisadel College boys school in Cape Coast. An excellent student, particularly in science and math, he received a scholarship to study chemical engineering at the University of Science and Technology Kumasi, Ghana. An honors student, he graduated in 1974 and was awarded a fellowship from the French government to study Chemical Engineering at the University of Science and Technology in Montpelier, France (USTL). While enrolled at USTL, he took part in a program at the Massachusetts Institute of Technology (MIT) and received a certificate in Modeling and Simulation of Chemical Processes from the university in 1977. A year later, he graduated from USTL with a PhD.

In 1980, Thomas travelled to the United States where he took a job with Air Product and Chemicals in Allentown, Pennsylvania. He was a research engineer in the chemical group division. One of his projects was to observe the mixing process in the Polyvinyl Alcohol Process Improvement Division. The process included injecting PVAC ( a polymer having a high resistance to to flow) with a catalyst. Inside of a thin film reactor which used a moving blade system. The resulting mixture would end up on a moving belt where it would cure into a white slab of Polyvinyl Alcohol, later cut into smaller pieces. A problem occurred when the mixture was of poor quality, as the resulting polyvinyl acetate did not cure properly, resulting in an usable product (and often causing a shutdown of the manufacturing process.

Mensah, after long research and an innovative use of high-tech video equipment was able to determine that when the centers of the vortices during the mixture process often trapped poorly mixed reactants , allowing them to proceed onto the moving belt. Thomas solved this by altering the blade configuration in the mixing process (as well as altering the notch depth). This redesign of the high speed thin film industrial mixers produced a much purer blend, thus improving the efficiency of the process and diminishing the delays which often shut down the manufacturing plant. He was rewarded by winning second prize in a prestigious research competition.

In 1983 he joined Corning Glass Works in Corning, New York as an engineer. He was brought on to help solve efficiency problems in the Corning Fiber Optic manufacturing process. Fiber optics refers to the design and application of optical fiber. Optical fibers refers to glass or plastic fiber through which light travels, usually carrying information. Fiber optics wires (or cables) are more efficient conductors of communication material than metal wire. Unfortunately, at that time it was difficult to increase the production of fiber optical material because the delicate glass fibers would break very easily if the production speed was increased. Thus, in the drawing and coating phase, the process was limited to producing only two meters per second of fiber optic stand.

Mensah saw that during the coating phase, bubbles were being trapped on the coating surface during the curing process. This caused inefficient losses of data. Using his knowledge of boundary layer theory, he solved this problem by injecting carbon dioxide gas near the boundary layer during the high speed coating process. This eliminated the bubbles from forming. He also was able to increase the strength of the glass allowing the manufacturing process to increase to 20 feet per send, a ten-fold improvement. He was awarded patents for each of these improvements along with two other patents for additional work.

In 1986, Thomas moved on to the AT&T Bell Laboratories in Georgia. At Bell he focused his attention on creating missile systems which utilized fiber optics for their guidance systems. In these systems, a small camera in the nose of the missile delivered images of a target through the fiber optic wires to the pilot who could then lock onto the target and hit them with extreme accuracy and precision. Dr. Mensah and his colleagues developed missiles that could use the fiber optic technology while traveling at MACH 1 (the speed of sound).

In addition to his work with fiber optics, Mensah found success in other areas of science. He has created superconductors for space communication, designed a system for creating solid state rechargeable cell phone batteries, developed new filament wound composite structures to be used to provide a light replacement for tank gun barrels among many other inventions. He would eventually become the Founder of georgia Aerospace which manufactured specialized composite structures for stealth aircraft.

In almost every aspect of his career,Thomas Mensah has met with enormous success on projects that have great historical significance. he has worked for private industry as well as for the Department of Energy and the Department of Defense and has been awarded seven patents. He has also received awards and recognition from the high tech community including the Corning Glass Works Industrial Outstanding Contributor Award for Innovation in Fiber Optics (1985), AT&T Bell Laboratories High Performance Award (1988), and the AIChE William Grimes Award for Excellence in Chemical Engineering (2007). He serves as a great model of turning great ambition into great success.



Dr. Thomas Mensah


Black Inventor -

Thomas Stewart

Many inventions were born from necessity and others for convenience. Others, however, are designed to lessen the drudgery and unpleasentness of daily tasks. Such was the invention of Thomas Stewart.

Cleaning floors had always meant scrubbing them on your hands and knees using a scrub brushes and rags. Thomas Stewart envisioned an easier, less painful way. Using a cloth connected to a stick handle and held in place by a metal clasp, Stewart presented the world with invention of the mop.

Valerie Thomas

Valerie Thomas - blackinventor.comAs a child, Valerie Thomas became fascinated with the mysteries of technology, tinkering with electronics with her father and reading books on electronics written for adolescent boys. The likelihood of her enjoying a career in science seemed bleak, as her all-girls high school did not push her to take advanced science or math classes or encourage her in that direction. Nonetheless, her curiosity was piqued and upon her graduation from high school, she set out on the path to become a scientist.

Thomas enrolled at Morgan State University and performed exceedingly well as a student, graduating with a degree in physics (one of only two women in her class to do so). She accepted a position with the National Aeronautics and Space Administration (NASA), serving as a data analyst. After establishing herself within the agency, she was asked to manage the “Landsat” project, an image processing system that would allow a satellite to transmit images from space.

In 1976 Thomas attended a scientific seminar where she viewed an exhibit demonstrating an illusion. The exhibit used concave mirrors to fool the viewer into believing that a light bulb was glowing even after it had been unscrewed from its socket. Thomas was fascinated by what she saw, and imagined the commercial opportunities for creating illusions in this manner.

In 1977 she began experimenting with flat mirrors and concave mirrors. Flat mirrors, of course, provide a reflection of an object which appear to lie behind the glass surface. A concave mirror, on the other hand, presents a reflection that appears to exist in front of the glass, thereby providing the illusion that they exist in a three-dimensional manner. Thomas believed that images, presented in this way could provide a more accurate, if not more interesting, manner of representing video data. She not only viewed the process as a potential breakthrough for commercial television, but also as scientific tool for NASA and its image delivery system.

Thomas applied for a patent for her process on December 28, 1978 and the patent was issued on October 21, 1980. The invention was similar to the technique of holographic production of image recording which uses coherent radiation and employs front wave reconstruction techniques which render the process unfeasible due to the enormous expense and complicated setup. Parabolic mirrors, however, can render these optical illusions with the use use of a concave mirror near the subject image and a second concave mirror at a remote site. In the description of her patent, the process is explained. “Optical illusions may be produced by parabolic mirrors wherein such images produced thereby are possessed with three dimensional attributes. The optical effect may be explained by the fact that the human eyes see an object from two view points separated laterally by about six centimeters. The two views show slightly different spatial relationships between near and near distant objects and the visual process fuses these stereoscopic views to a single three dimensional impression. The same parallax view of an object may be experienced upon reflection of an object seen from a concave mirror.” ( The Illusion Transmitter would thus enable the users to render three-dimensional illusions in real-time.

Valerie Thomas continued working for NASA until 1995 when she retired. In addition to her work with the Illusion Transmitter she designed programs to research Halley’s comet and ozone holes. She received numerous awards for her service, including the GSFC Award of Merit and the NASA Equal Opportunity Medal. In her career, she showed that the magic of fascination can often lead to concrete scientific applications for real-world problem-solving.

Black Inventor -

William Purvis

William Purvis realized how much of an inconvenience it was to have to carry around a bottle of ink whenever you needed to sign a contract or fill out legal papers. He therefore decided to do something about it.

On January 7, 1890, Purvis received a patent for the fountain pen. The pen eliminated the need for an ink bottle by storing ink within a reservoir within the pen which is then fed to the pen’s tip. Of his accomplishment, Purvis said, “the object of my invention is to provide a simple, durable, and inexpensive construction of a fountain pen adapted to general use and which may be carried in the pocket.” The creation of the fountain pen has made office work cleaner and less expensive for businesses all over the world.

In addition to his fountain pen, Purvis, a resident of Philadelphia, Pennsylvania, also successfully patented a number of other inventions. Between 1884 and 1897 he patented bag machines, a bag fastener, a hand stamp, an electric railway device, an electric railway switch and a magnetic car balancing device. He also is believed to have invented , yet not patented several other devices such as the edge cutter found on aluminum foil, cling wrap and wax paper boxes.

Black Inventor -

Willis Johnson

On February 5, 1884, Willis Johnson patented a device made up of a handle attached to a series of spring-like whisk wires used to help mix ingredients. Prior to his eggbeater, all mixing of ingredients was done by hand.and was quite labor-intensive and time-consuming.