1. Common dredge. 2. Chester rake-dredge. 3 and 4. Blake dredge.
In: "Report on the Construction and Outfit of the United States Fish Commission
Steamer ALBATROSS", by Lieutenant-Commander Z. L. Tanner, U. S. N. United
States Commission of Fish and Fisheries. Part XI. Report of the Commissioner
for 1883. Plate XLIX, p. 111.