A Fathometer is an old genericized trademark for an instrument which measures?
Herbert Grove Dorsey 1923, which is also referred to as the Dorsey Fathometer by the director of the U. S. Coast and Geodetic Survey in 1934. It worked by sending a high pitched sound through the water. It traveled to the bottom at a known speed and returned an echo at the rate of four pings per second. This could then be measured and calculated as to the depth since sound travels at a precise speed in water. The "Fathometer" was so named by Dorsey because it measures fathoms. The Dorsey Fathometer instrument was used to get a precise measurement of water depth.
Generic trademark Generic trademark A generic trademark, also known as a genericized trademark or proprietary eponym, is a trademark or brand name that, due to its popularity or significance, has become the generic name for, or synonymous with, a general class of product or service, usually against the intentions of the trademark's holder. The process of a product's name becoming genericized is known as genericide. A trademark is said to become "genericized" when it begins as a distinctive product identifier but changes in meaning to become generic. This typically happens when the products or services with which the trademark is associated have