Sounding machine with Negretti and Zambra deep-sea thermometer descending.
In: "Report on the Construction and Work in 1880 of United States Fish
Commission Steamer FISH-HAWK", by Lieutenant Zera Luther Tanner, U. S. N.
United States Commission of Fish and Fisheries.
Part IX. Report of the Commissioner for 1881. Plate XIII, p. 53.