Sarah Mather

Background

Sarah Mather (fl. 1840s–1860s) was an American inventor best known for developing an early submarine telescope, a device that enabled visual inspection of submerged objects without the need for diving or dry docking. Her invention contributed to advancements in both commercial and military maritime practices and was one of the earliest documented underwater observation technologies. Mather was among the few women in 19th-century America to be granted a United States patent for a technological invention, making her an early figure in the history of women in science and engineering.

Sarah Mather (born Sarah Porter Stinson or Stimson, c. 1796) lived in Brooklyn, New York. In 1819, she married Harlow Mather, and the couple had several children, including a daughter, Olive M. Devoe. Late in her life, Mather was involved in charitable work supporting children of Civil War soldiers and participated in literary and publishing activities. Although detailed biographical information about her life is scarce, she is known to have been active as an inventor during a period when women were largely excluded from formal scientific and technical institutions. Social and legal constraints of the time made it difficult for women to be acknowledged as inventors, and most patents were filed by men.

There is also evidence that Mather worked closely with her son, who co-filed a later improvement patent with her in 1864. This collaboration suggests that her inventive work may have taken place within a family context that supported technological experimentation, which was one of the few avenues available to women innovators of her era.

Invention of the submarine telescope

The Submarine Telescope was a device that allowed observers to view items below the surface of the water from above. Her work as an inventor occurred during a time when women were largely excluded from education and employment in science, engineering, and patent law.

Sarah Mather was granted a United States Patent No. 3,755 dated April 16, 1845 for an Apparatus for Examining Objects Under Water. In describing her invention in the patent application, she stated that the device consisted of a tube having a lamp attached to one end of it and a telescope at the other end for observing underwater objects. As she explained in her patent application, the function of her invention was quite simple yet highly valuable: persons located above the surface of the water can visually examine objects located beneath the surface without requiring direct immersion into the water. Further, she incorporated safety and watertight aspects into her design demonstrating her consideration of several technical issues associated with providing light and optical systems to operate underwater.[1]

The problem that Mather's invention attempted to solve was significant. Ship owners, mariners, engineers and harbor employees lacked sufficient means to visually assess underwater structures (e.g., examine ship hulls, locate debris, identify underwater obstacles, etc.) prior to the availability of Mather's invention. Assessing an object underwater could be hazardous and/or laborious. Mather's invention presented a safe and efficient method for performing these tasks. The patent itself noted that the invention could be applied to: inspect vessel hulls; detect underwater objects; facilitate fishing; aid in rock blasting operations to clear channels; provide assistance in laying foundations; and study geological formations. The number of uses for Mather's invention demonstrate that it was a functional tool developed to meet specific needs within both the maritime industry and general commercial/industrial sectors.[1][3].

It is also worth noting that Mather's invention occurred at a time when advancements in water transportation technology, naval construction technology and harbor infrastructure were essential for national and regional economic progress. There existed considerable cost savings in terms of time and expense related to assessing the bottom of ships while they remain submerged in water. Additionally, there was increased risk involved with poor underwater visibility. Accounts of Mather's work indicate that after its introduction, the submarine telescope gained particular usefulness in naval contexts and may have had additional wartime significance during the Civil War era due to the increasing importance of underwater threats and ship inspections.[3]. Although it is difficult to verify the full extent to which the submarine telescope was utilized during this time, it is evident that the device would have been beneficial in a time period when the ability to see underwater had strategic implications.[3].