Piano-wire sounding maching developed by Sir William Thomson, later Lord Kelvin.
This machine was used by George Belknap to sound from the U. S. S. TUSCARORA in
a cable survey across the North Pacific. He shipped it to Charles Sigsbee on
the C&GS Steamer BLAKE who modified the machine to become the Sigsbee Sounding
Machine. In: "150 Years of Service on the Seas ...." Call No.GC29.2.U5 P5.