8 Natural History Bulletin. 



desired information given with great care and courtesy. 

 Among those who kindly rendered aid in this direction were 

 Hon. Marshall McDonald. United States Commissioner of Fish 

 and Fisheries; Mr. James E. Benedict, who was naturalist in 

 charge of the '• Albatross " during her first cruise in the West 

 Indies; Captain J. W. Collins, Commander of the United 

 States Sailing Dredger "Grampus;" and especially Doctor 

 Alexander Agassiz. whose long experience as a naturalist in 

 charge of the various " Blake " expeditions in the West Indies 

 and Florida Keys made his advice of the utmost value. The 

 amount of trouble this gentleman took to help entire strangers 

 with detailed plans of equipment best suited to their wants, 

 was almost as astonishing as it was gratifying. He alone, of 

 all our kind advisers, thought Professor Weld's plan of using 

 iron instead of hemp rope practicable. The others advised 

 the use of Italian hemp rope. The final adopting of the iron 

 instead of the hemp proved a most valuable and practical idea. 

 After once having used it. -we felt that the success of our 

 deep water work was assured. Of course iron rope had 

 already superseded hemp in deep-sea work with steamers: 

 but our vessel must necessarily be a sailing craft, and scien- 

 tific dredging had never before, so far as we could learn, been 

 attempted with iron ropes on a sail vessel. The many points 

 of superiority of iron over hemp will be noted further on. 



It soon became evident that even the simplest sort of 

 donkey engine . for workino- the dredire was bevond our 

 means, and a device that could be worked by hand was 

 substituted. This consisted in a hoisting machine, technicalh' 

 known as a •• crab," constructed after plans by ProfessorWeld. 

 It consisted essentially of a horizontal drum, tifteen inches in 

 diameter and thirty inches long, resting on a hea\\' iron 

 frame bolted to the deck. This drum w;is proxided with a 

 single and double purchase for cranks, by which a sufiicient 

 degree of power could be applied to meet an\- demands 

 likely to be made upon the machine. The lowering of the 

 dredge was regulated by a powerful friction brake, which 

 kept the speed of the descending dredge under complete con- 



