U.S . Coast and Geodetic Survey
Which employer did Herbert Grove Dorsey work for from 1926 to 1927?
Herbert Grove Dorsey Early life . Dorsey was born in Kirkersville , Ohio on April 24 , 1876 . His parents were Edwin Jackson and Mary Elma ( Grove ) Dorsey . Family . On June 21 , 1900 , Dorsey married Virginia Rowlett in Palmetto , Florida . Their children were Herbert Grove , Jr . and William Rowlett . Education . Dorsey received a Bachelor of Science degree from Johns Hopkins University in 1897 . He did post-graduate work at Hopkins in 1897 and received a Master of Science honorary degree from Denison University in 1898 . He did post-graduate work at Harvard University in 1900–1901 and earned a Ph . D . from Cornell University in 1908 . Societies . He was a member of Beta Theta Pi . Career . Dorsey taught physics at the University of Maine from 1898–1900 . He was head of the physics and electricity departments at the University of Florida from 1901–03 and at the University of Rochester from 1903–1904 . Dorsey was assistant instructor in physics from 1904–1905 , and instructor of physics from 1905–1910 at Cornell University . From 1910–1911 , Dorsey worked as an electrical engineer in the research laboratory of Western Electric Company . He worked as an inventor at the National Cash Register Company from 1912–16 . He was a physicist for the Hammond Radio Research Laboratory in Gloucester , Massachusetts from 1916–1921 and for the Submarine Signal Company from 1922–1925 . Starting in 1926 , he worked for the U.S . Coast and Geodetic Survey as the principal electrical engineer , continuing through the 1930s . Inventions . Some of his patented inventions were an automatic deposit box , 1908 ; an electric indicating system for railways , 1908 ; a telephone circuit , 1912 ; a telephone apparatus improvement , 1912 ; a device for graphically reproducing sound waves , 1912 ; a submarine mine , 1916 ; an electrical credit system , 1916 ; a safety device for electrical circuits , 1916 ; a submarine control system , 1918 ; a telegraphy device , 1921 ; and an auto chain applicator , 1921 . Fathometer . Dorsey invented the practical fathometer in 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 . It could measure depths from 8 to 3000 fathoms . The accuracy of the instrument was to within three inches and it could be measured in a millisecond . There were different models of the fathometer made initially by the Submarine Signal Company . The indicator of the Dorsey Fathometer was a neon tube on a rotating disc . The instrument looked like a clock and was in the bridge of a ship . The transmitting and receiving electronics were usually below the deckhouse . Before this instrument a ship had slow down considerably or stop to take soundings to get the depth . With Dorseys Fathometer a ship could go at full speed and get the measurements . Works . - Coefficients of linear expansion at low temperatures ( 1908 ) - The Dorsey Fathometer Washington Academy of Sciences ( 1935 ) External links . - WorldCat Publications - Herbert Grove Dorset – patent US1730411A - Device for graphically reproducing sound-waves . - Fathometer to measure the depth of water , 1928 . - Radio Talk on Echo Sounding by Dr . H . G . Dorsey