546 FISHERIES OF THE UNITED STATES. [34] 



system, is used for illuminatiug the surrounding surface of the sea. A 

 powerful submarine lamp is also provided, which can be lowered to any 

 depth not exceeding 1,000 feet, to be used in deep-sea exploration. 



Among the various appliances the following may be briefly mentioned, 

 viz: the Sigsbee deep-sea sounding machine, sounding rods, water cups, 

 and gravitating trap for collecting specimens at known intermediate 

 depths, built by D. Ballauf, Washington, D. 0. ; Tanner's sounding 

 machine for depths under 1,000 fathoms and for navigational pur- 

 poses; the dredging boom, 36 feet in length and 10 inches in diameter, 

 the heel pivoted to the forward part of the foremast, 7 feet 2 inches 

 above the deck; the dredging block at the boom end, the sheave and 

 register at the heel of the boom for indicating the length of dredge rope 

 out, and the accumulator at the foremast head, arranged to prevent 

 jerking strains on the rope (the accumulator used is of the form recom- 

 mended by Commander Sigsbee, United States Navy) ; the Negretti and 

 Zambra deep-sea thermometers, with the Bailie and Tanner improved 

 cases; the Chester rake dredge; the well known beam trawl; the deep- 

 sea trawl; the Chester towing net; the tangles, table sieve, seines, trawl 

 lines, &c, 



INDEX TO THE DETAILED PLANS OF THE STEAMER ALBATROSS. 

 POOP-HOUSE AND FORECASTLE DECKS. 



1. Forecastle. 



2. Wooden bitts. 



3. Fish-davit. 



4. Capstan (connected with steam-winch). 



5. 3-inch rifled howitzer. 



6. Sigsbee deep-sea sounding machine. 



7. Top of pilot-house. 



8. Top of deck-house. 



9. Bridge. 



10. Sky-light over chart-room and laboratory. 



11. Whale-boat. 



12. Seine- boat. 



13. Standard compass. 



14. Smoke-stack. 



15. Ventilator to fire-room. 



16. Sky- light over drum-room and galley 



17. Steam gig. (Herreshoff.) 



18. Steam launch. (Herreshoff.) 



19. Engine-room sky-light. 



20. Dingey. 



21. After-compass. 



22. Mainmast. 



23. Main-boom. 



